CVE Feed

In the Linux kernel, the following vulnerability has been resolved: ASoC: rsnd: Fix potential out-of-bounds access of component_dais[] component_dais[RSND_MAX_COMPONENT] is initially zero-initialized and later populated in rsnd_dai_of_node(). However, the existing boundary check: if (i >= RSND_MAX_COMPONENT) does not guarantee that the last valid element remains zero. As a result, the loop can rely on component_dais[RSND_MAX_COMPONENT] being zero, which may lead to an out-of-bounds access. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: net: ena: PHC: Check return code before setting timestamp output ena_phc_gettimex64() is setting the output parameter regardless of whether ena_com_phc_get_timestamp() succeeded or failed. When ena_com_phc_get_timestamp() returns an error, the timestamp parameter may contain uninitialized stack memory (e.g., when PHC is disabled or in blocked state) or invalid hardware values. Passing these to userspace via the PTP ioctl is both a security issue (information leak) and a correctness bug. Fix by checking the return code after releasing the lock and only setting the output timestamp on success.

In the Linux kernel, the following vulnerability has been resolved: batman-adv: tp_meter: avoid divide-by-zero for dec_cwnd The cwnd is always MSS <= cwnd <= 0x20000000. But the calculation in batadv_tp_update_cwnd() assumes unsigned 32 bit arithmetics. ((mss * 8) ** 2) / (cwnd * 8) In case cwnd is actually 0x20000000, it will be shifted by 3 bit to the left end up at 0x100000000 or U32_MAX + 1. It will therefore wrap around and be 0 - resulting in: ((mss * 8) ** 2) / 0 This is of course invalid and cannot be calculated. The calculation should must be simplified to avoid this overflow: (mss ** 2) * 8 / cwnd It will keep the precision enhancement from the scaling (by 8) but avoid the overflow in the divisor. In theory, there could still be an overflow in the dividend. It is at the moment fixed to BATADV_TP_PLEN in batadv_tp_recv_ack() - so it is not an imminent problem. But allowing it to use the whole u32 bit range, would mean that it can still use up to 67 bits. To keep this calculation safe for 32 bit arithmetic, mss must never use more than floor((32 - 3) / 2) bits - or in other words: must never be larger than 16383.

In the Linux kernel, the following vulnerability has been resolved: batman-adv: v: prevent OGM aggregation on disabled hardif When an interface gets disabled, the worker is correctly disabled by batadv_hardif_disable_interface() -> ... -> batadv_v_ogm_iface_disable(). In this process, the skb aggr_list is also freed. But batadv_v_ogm_send_meshif() can still queue new skbs (via batadv_v_ogm_queue_on_if()) to the aggr_list. This will only stop after all cores can no longer find the RCU protected list of hard interfaces. These queued skbs will never be freed or consumed by batadv_v_ogm_aggr_work. The batadv_v_ogm_iface_disable() function must block batadv_v_ogm_queue_on_if() to avoid leak of skbs.

In the Linux kernel, the following vulnerability has been resolved: batman-adv: tp_meter: restrict number of unacked list entries When the unacked_list is unbound, an attacker could send messages with small lengths and appropriated seqno + gaps to force the receiver to allocate more and more unacked_list entries. And the end either causing an out-of-memory situation or increase the management overhead for the (large) list that significant portions of CPU cycles are wasted in searching through the list. When limiting the list to a specific number, it is important to still correctly add a new entry to the list. But if the list became larger than the limit, the last entry of the list (with the highest seqno) must be dropped to still allow the earlier seqnos to finish and therefore to continue the process. Otherwise, the process might get stuck with too high seqnos which are not handled by batadv_tp_ack_unordered().

In the Linux kernel, the following vulnerability has been resolved: ntfs3: reject direct userspace writes to reserved $LX* xattrs NTFS3 uses $LXUID, $LXGID, $LXMOD and $LXDEV as internal WSL permission metadata and reloads them into i_uid, i_gid and i_mode from ntfs_get_wsl_perm(). Because the empty-prefix xattr handler also lets file owners call setxattr() on these names directly, an unprivileged writer on a writable ntfs3 mount can plant root ownership and S_ISUID on their own file and gain euid 0 after inode reload. Reject direct userspace writes to the reserved $LX* names. Internal ntfs3 metadata updates are unchanged because ntfs_save_wsl_perm() writes them via ntfs_set_ea() directly. [[email protected]: added an additional check for non privileged users]

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: add wcid publish check in mt76_sta_add Since mt7925_mac_sta_add publishes wcid, add publish check in mt76_sta_add to avoid reinitializing the wcid->poll_list. Found dev->sta_poll_list corruption when using mt7925 and 7.1-rc4. According to the corruption information, prev->next was changed to itself. wlan0: disconnect from AP 90:fb:5d:94:8b:e3 for new auth to 90:fb:5d:94:8b:e2 wlan0: authenticate with 90:fb:5d:94:8b:e2 (local address=84:9e:56:9c:7e:6b) wlan0: send auth to 90:fb:5d:94:8b:e2 (try 1/3) slab kmalloc-8k start ffff8c80958a6000 pointer offset 4160 size 8192 list_add corruption. prev->next should be next (ffff8c808a7488f8), but was ffff8c80958a7040. (prev=ffff8c80958a7040). mt76_wcid_add_poll+0x95/0xd0 [mt76] mt7925_mac_add_txs.part.0+0xa5/0xe0 [mt7925_common] mt7925_rx_check+0xa7/0xc0 [mt7925_common] mt76_dma_rx_poll+0x50d/0x790 [mt76] mt792x_poll_rx+0x52/0xe0 [mt792x_lib]

In the Linux kernel, the following vulnerability has been resolved: mac802154: llsec: add skb_cow_data() before in-place crypto llsec_do_encrypt_unauth(), llsec_do_encrypt_auth(), llsec_do_decrypt_unauth(), and llsec_do_decrypt_auth() all perform in-place cryptographic transformations on skb data. They build a scatterlist with sg_init_one() pointing into the skb's linear data area and then pass the same scatterlist as both src and dst to the crypto API (e.g. crypto_skcipher_encrypt/decrypt, crypto_aead_encrypt/decrypt). On the RX path, __ieee802154_rx_handle_packet() clones the received skb before handing it to each subscriber via ieee802154_subif_frame(). The cloned skb shares the same underlying data buffer via reference counting. When llsec_do_decrypt() subsequently modifies this shared buffer in place, it corrupts data that other clones -- potentially belonging to other sockets or subsystems -- still reference. On the TX path, similar data sharing can occur when an skb's head has been cloned (skb_cloned() returns true). The fix is to call skb_cow_data() before performing any in-place crypto operation. skb_cow_data() ensures that the skb's data area is not shared: if the skb head is cloned or the data spans multiple fragments, it copies the data into a private buffer that can be safely modified in place. This is the same pattern used by: - ESP (net/ipv4/esp4.c, net/ipv6/esp6.c) - MACsec (drivers/net/macsec.c) - WireGuard (drivers/net/wireguard/receive.c) - TIPC (net/tipc/crypto.c) Without this guard, in-place crypto on shared skb data leads to: - Silent data corruption of other skb clones - Use-after-free when the crypto API scatterwalk writes through a page that has already been freed by another clone's kfree_skb() - Kernel crashes under concurrent 802.15.4 traffic with security enabled (KASAN/KMSAN reports slab-use-after-free) Found by 0sec (https://0sec.ai) using automated source analysis.

In the Linux kernel, the following vulnerability has been resolved: gcov: use atomic counter updates to fix concurrent access crashes GCC's GCOV instrumentation can merge global branch counters with loop induction variables as an optimization. In inflate_fast(), the inner copy loops get transformed so that the GCOV counter value is loaded multiple times to compute the loop base address, start index, and end bound. Since GCOV counters are global (not per-CPU), concurrent execution on different CPUs causes the counter to change between loads, producing inconsistent values and out-of-bounds memory writes. The crash manifests during IPComp (IP Payload Compression) processing when inflate_fast() runs concurrently on multiple CPUs: BUG: unable to handle page fault for address: ffffd0a3c0902ffa RIP: inflate_fast+1431 Call Trace: zlib_inflate __deflate_decompress crypto_comp_decompress ipcomp_decompress [xfrm_ipcomp] ipcomp_input [xfrm_ipcomp] xfrm_input At the crash point, the compiler generated three loads from the same global GCOV counter (__gcov0.inflate_fast+216) to compute base, start, and end for an indexed loop. Another CPU modified the counter between loads, making the values inconsistent - the write went 3.4 MB past a 65 KB buffer. Add -fprofile-update=prefer-atomic to CFLAGS_GCOV at the global level in the top-level Makefile, guarded by a try-run compile test. The test compiles a minimal program with and without -fprofile-update=prefer-atomic using the full KBUILD_CFLAGS, then compares undefined symbols in the resulting object files. If prefer-atomic introduces new undefined references (such as __atomic_fetch_add_8 on i386 or __aarch64_ldadd8_relax on arm64 with outline-atomics), the flag is not added -- the kernel does not link against libatomic. On architectures where GCC inlines 64-bit atomic counter updates (x86_64, s390, ...) the test passes and the flag is enabled, preventing the compiler from merging counters with loop induction variables and fixing the observed concurrent-access crash. On architectures where the flag would introduce libatomic dependencies, it is silently omitted and behaviour is no worse than before this patch. Move the CFLAGS_GCOV block from its original position (before the arch Makefile include) to after the core KBUILD_CFLAGS assignments but before the scripts/Makefile.gcc-plugins include. This placement ensures the try-run test sees arch-specific flags (-m32, -march=, -mno-outline-atomics) while avoiding GCC plugin flags (-fplugin=) that would break the test on clean builds when plugin shared objects do not yet exist.

In the Linux kernel, the following vulnerability has been resolved: KEYS: fix overflow in keyctl_pkey_params_get_2() The length for the internal output buffer is calculated incorrectly, which can result overflow when a too small buffer is provided. Fix the bug by allocating internal output with the size of the maximum length of the cryptographic primitive instead of caller provided size.

In the Linux kernel, the following vulnerability has been resolved: keys: Pin request_key_auth payload in instantiate paths A: request_key() B: KEYCTL_INSTANTIATE_IOV ================ ========================= create auth key store rka in auth key wait for helper get auth key load rka from auth key copy user payload sleep on #PF helper completed detach and free rka destroy auth key wake up use rka->target_key **USE-AFTER-FREE** Give request_key_auth payloads a refcount. Take a payload reference while authkey->sem stabilizes the payload and revocation state. Hold that reference across the instantiate and reject paths. Drop the auth key owning reference from revoke and destroy. [jarkko: Replaced the first two paragraphs of text with an actual concurrency scenario.]

In the Linux kernel, the following vulnerability has been resolved: wifi: ath11k: fix warning when unbinding If there is an error during some initialization related to firmware, the buffers dp->tx_ring[i].tx_status are released. However this is released again when the device is unbinded (ath11k_pci), and we get: WARNING: CPU: 0 PID: 6231 at mm/slub.c:4368 free_large_kmalloc+0x57/0x90 Call Trace: free_large_kmalloc ath11k_dp_free ath11k_core_deinit ath11k_pci_remove ... The issue is always reproducible from a VM because the MSI addressing initialization is failing. In order to fix the issue, just set the buffers to NULL after releasing in order to avoid the double free.

In the Linux kernel, the following vulnerability has been resolved: wifi: rtw88: usb: fix memory leaks on USB write failures When rtw_usb_write_port() fails to submit a USB Request Block (URB) (e.g., due to device disconnect or ENOMEM), the completion callback is never executed. Currently, the driver ignores the return value of rtw_usb_write_port() in rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these functions rely on the completion callback to free the socket buffers (skbs) and the transaction control block (txcb), a submission failure results in: 1. A memory leak of the allocated skb in rtw_usb_write_data(). 2. A memory leak of the txcb structure and all aggregated skbs in rtw_usb_tx_agg_skb(). Fix this by checking the return value of rtw_usb_write_port(). If it fails, explicitly free the skb in rtw_usb_write_data(), and properly purge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb(). The issue was discovered in practice during device disconnect/reconnect scenarios and memory pressure conditions. Tested by verifying normal TX operation continues after the fix without regressions.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix missing read bio submission on large folio error f2fs_read_data_large_folio() can keep a read bio across multiple readahead folios. If a later folio hits an error before any of its blocks are added to the bio, folio_in_bio is false and the current error path returns immediately after ending that folio. This can leave the bio accumulated for earlier folios unsubmitted. Those folios then never receive read completion, and readers can wait indefinitely on the locked folios. Route errors through the common out path so any pending bio is submitted before returning. Stop consuming more readahead folios once an error is seen, and only wait on and clear the current folio when it was actually added to the bio.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on f2fs_get_node_folio_ra() kernel BUG at fs/f2fs/file.c:845! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:f2fs_do_truncate_blocks+0x1115/0x1140 fs/f2fs/file.c:845 Code: fc fc 90 0f 0b e8 8b 9d 9a fd 90 0f 0b e8 83 9d 9a fd 48 89 df 48 c7 c6 60 d1 1a 8c e8 54 f1 fc fc 90 0f 0b e8 6c 9d 9a fd 90 <0f> 0b e8 64 9d 9a fd 90 0f 0b 90 e9 93 fd ff ff e8 56 9d 9a fd 90 RSP: 0018:ffffc9000e4474c0 EFLAGS: 00010283 RAX: ffffffff842b1d34 RBX: 0000000000000003 RCX: 0000000000100000 RDX: ffffc9000f03a000 RSI: 0000000000035503 RDI: 0000000000035504 RBP: ffffc9000e447608 R08: ffff8880123b0000 R09: 0000000000000002 R10: 00000000fffffffe R11: 0000000000000002 R12: 0000000000000001 R13: 0000000000000000 R14: 1ffff92001c88ea0 R15: 00000000ffff039c FS: 00007f7e02ee36c0(0000) GS:ffff88808c887000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff0305c4000 CR3: 0000000012d4c000 CR4: 0000000000352ef0 Call Trace: <TASK> f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:882 f2fs_truncate+0x471/0x7c0 fs/f2fs/file.c:940 f2fs_evict_inode+0xa3f/0x1ac0 fs/f2fs/inode.c:907 evict+0x61e/0xb10 fs/inode.c:841 f2fs_fill_super+0x5f43/0x78f0 fs/f2fs/super.c:5224 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f count = ADDRS_PER_PAGE(dn.node_folio, inode); count -= dn.ofs_in_node; f2fs_bug_on(sbi, count < 0); The fuzz test will trigger above bug_on in f2fs. The root cause should be: in the corrupted inode, there is a direct node which has the same ino and nid in its footer, so in f2fs_do_truncate_blocks(), after f2fs_get_dnode_of_data() finds such dnode: 1) ADDRS_PER_PAGE(dn.node_folio, inode) will return 923 2) once dn.ofs_in_node points to addr[923, 1017] Then it will trigger the system panic. Let's introduce NODE_TYPE_NON_IXNODE to indicate current node should not be an inode or xattr node, and then use it in below path to detect inconsistent node chain in inode mapping table: - f2fs_do_truncate_blocks - f2fs_get_dnode_of_data - f2fs_get_node_folio_ra - __get_node_folio - f2fs_sanity_check_node_footer - case NODE_TYPE_NON_IXNODE -> check whether it is inode|xnode

In the Linux kernel, the following vulnerability has been resolved: f2fs: validate ACL entry sizes in f2fs_acl_from_disk() f2fs_acl_count() only validates the aggregate ACL xattr length. A malformed ACL can still place ACL_USER or ACL_GROUP in a slot that only contains struct f2fs_acl_entry_short bytes, and f2fs_acl_from_disk() then reads entry->e_id before verifying that a full entry fits. Require a short entry before reading e_tag and e_perm, and require a full entry before reading e_id for ACL_USER and ACL_GROUP. Return -EFSCORRUPTED from these new truncated-entry checks, while keeping the pre-existing -EINVAL paths unchanged. Validation reproduced this kernel report: KASAN slab-out-of-bounds in __f2fs_get_acl+0x6fb/0x7e0 RIP: 0033:0x7f4b835ea7aa The buggy address belongs to the object at ffff888114589960 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes to the right of allocated 8-byte region [ffff888114589960, ffff888114589968) Read of size 4 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xce/0x630 (?:?) __f2fs_get_acl+0x6fb/0x7e0 (fs/f2fs/acl.c:169) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x224/0x430 (?:?) kasan_report+0xe0/0x110 (?:?) __f2fs_get_acl+0x5/0x7e0 (fs/f2fs/acl.c:169) __get_acl+0x281/0x380 (?:?) vfs_get_acl+0x10b/0x190 (?:?) do_get_acl+0x2a/0x410 (?:?) do_get_acl+0x9/0x410 (?:?) do_getxattr+0xe8/0x260 (?:?) filename_getxattr+0xd1/0x140 (?:?) do_getname+0x2d/0x2d0 (?:?) path_getxattrat+0x16c/0x200 (?:?) lock_release+0xc8/0x290 (?:?) cgroup_update_frozen+0x9d/0x320 (?:?) lockdep_hardirqs_on_prepare+0xea/0x1a0 (?:?) trace_hardirqs_on+0x1a/0x170 (?:?) _raw_spin_unlock_irq+0x28/0x50 (?:?) do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)

In the Linux kernel, the following vulnerability has been resolved: Revert "f2fs: remove non-uptodate folio from the page cache in move_data_block" This reverts commit 9609dd704725a40cd63d915f2ab6c44248a44598. The kernel panics are keeping to be reported especially when the f2fs partition get almost full. By investigation, we find that the reason is one f2fs page got freed to buddy without being deleted from LRU and the root cause is the race happened in [2] which is enrolled by this commit. There are 3 race processes in this scenario, please find below for their main activities. The changed code in move_data_block() lets the GC path evict the tail-end folio from the page cache through folio_end_dropbehind(). Once folio_unmap_invalidate() removes the folio from mapping->i_pages, the page-cache references for all pages in the folio are dropped. The folio is then kept alive only by temporary external references, which allows a later split to operate on a folio whose subpages are no longer protected by page-cache references. After the page-cache references are gone, split_folio_to_order() can split the big folio into individual pages and put the resulting subpages back on the LRU. For tail pages beyond EOF, split removes them from the page cache and drops their page-cache references. A tail page can then remain on the LRU with PG_lru set while holding only the split caller's temporary reference. When free_folio_and_swap_cache() drops that final reference, the page enters the final folio_put() release path. In parallel, folio_isolate_lru() can observe the same tail page with a non-zero refcount and PG_lru set. It clears PG_lru before taking its own reference. If this races with the final folio_put() from the split path, __folio_put() sees PG_lru already cleared and skips lruvec_del_folio(). The page is then freed back to the allocator while its lru links are still present in the LRU list. A later LRU operation on a neighboring page detects the stale link and reports list corruption. [1] [ 22.486082] list_del corruption. next->prev should be fffffffec10e0ac8, but was dead000000000122. (next=fffffffec10e0a88) [ 22.486130] ------------[ cut here ]------------ [ 22.486134] kernel BUG at lib/list_debug.c:67! [ 22.486141] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP [ 22.488502] Tainted: [W]=WARN, [O]=OOT_MODULE [ 22.488506] Hardware name: Spreadtrum UMS9230 1H10 SoC (DT) [ 22.488511] pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 22.488517] pc : __list_del_entry_valid_or_report+0x14c/0x154 [ 22.488531] lr : __list_del_entry_valid_or_report+0x14c/0x154 [ 22.488539] sp : ffffffc08006b830 [ 22.488542] x29: ffffffc08006b868 x28: 0000000000003020 x27: 0000000000000000 [ 22.488553] x26: 0000000000000000 x25: 0000000000000004 x24: fffffffec10e0ac0 [ 22.488564] x23: 00000000000000e8 x22: 0000000000000024 x21: dead000000000122 [ 22.488574] x20: fffffffec10e0a88 x19: fffffffec10e0ac8 x18: ffffffc080061060 [ 22.488585] x17: 20747562202c3863 x16: 6130653031636566 x15: 0000000000000058 [ 22.488595] x14: 0000000000000004 x13: ffffff80f91e0000 x12: 0000000000000003 [ 22.488605] x11: 0000000000000003 x10: 0000000000000001 x9 : ffe85721f0e25f00 [ 22.488615] x8 : ffe85721f0e25f00 x7 : 0000000000000000 x6 : 6c65645f7473696c [ 22.488625] x5 : ffffffed39b23026 x4 : 0000000000000000 x3 : 0000000000000010 [ 22.488636] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 000000000000006d [ 22.488647] Call trace: [ 22.488651] __list_del_entry_valid_or_report+0x14c/0x154 (P) [ 22.488661] __folio_put+0x2bc/0x434 [ 22.488670] folio_put+0x28/0x58 [ 22.488678] do_garbage_collect+0x1a34/0x2584 [ 22.488689] f2fs_gc+0x230/0x9b4 [ 22.488697] f2fs_fallocate+0xb90/0xdf4 [ 22.488706] vfs_fallocate+0x1b4/0x2bc [ 22.488716] __arm64_sys_fallocate+0x44/0x78 [ 22.488725] invoke_syscall+0x58/0xe4 [ 22.488732] do_el0_svc+0x48/0xdc [ 22.488739] el0 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix incorrect FI_NO_EXTENT handling in __destroy_extent_node() When __destroy_extent_node() sets the inode flag FI_NO_EXTENT, it does not reset the length of the largest extent to 0 and update the inode folio. Since modifications to the extent tree are disallowed afterward, the cached largest extent may become stale. This can trigger the following error in xfstests generic/388: F2FS-fs (dm-0): sanity_check_extent_cache: inode (ino=1761) extent info [220057, 57, 6] is incorrect, run fsck to fix In the f2fs_drop_inode path, __destroy_extent_node() does not need to guarantee that et->node_cnt is 0, because concurrency with writeback is expected in this path, and writeback may update the extent cache. This patch reverts commit ed78aeebef05 ("f2fs: fix node_cnt race between extent node destroy and writeback"), and remove the unnecessary zero check of et->node_cnt.

In the Linux kernel, the following vulnerability has been resolved: f2fs: read COW data with the original inode during atomic write When updating an atomic-write file, f2fs_write_begin() may read the previously written data back from the COW inode: prepare_atomic_write_begin() locates the block in the COW inode and sets use_cow, and the read bio is then built with the COW inode: f2fs_submit_page_read(use_cow ? F2FS_I(inode)->cow_inode : inode, ...); and f2fs_grab_read_bio() decides whether to schedule fs-layer decryption (STEP_DECRYPT) for the bio based on that inode via fscrypt_inode_uses_fs_layer_crypto(). However, the folio being filled belongs to the original inode (folio->mapping->host == inode), and the data stored in the COW block was encrypted (or left as plaintext) using the original inode's context, not the COW inode's -- see f2fs_encrypt_one_page(), which keys off fio->page->mapping->host. fscrypt_decrypt_pagecache_blocks() likewise operates on folio->mapping->host. The COW inode is created as a tmpfile in the parent directory and inherits its encryption policy from there. With test_dummy_encryption the newly created COW inode gets the dummy policy and becomes encrypted, while a pre-existing regular file -- created before the policy applied, e.g. already present in the on-disk image -- stays unencrypted. The read path then sets STEP_DECRYPT based on the encrypted COW inode and calls fscrypt_decrypt_pagecache_blocks() on a folio whose host (the unencrypted original inode) has a NULL ->i_crypt_info, dereferencing it: Oops: general protection fault, probably for non-canonical address ... KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:fscrypt_decrypt_pagecache_blocks+0xa0/0x310 Workqueue: f2fs_post_read_wq f2fs_post_read_work Call Trace: fscrypt_decrypt_bio+0x1eb/0x340 f2fs_post_read_work+0xba/0x140 process_one_work+0x91c/0x1a40 worker_thread+0x677/0xe90 kthread+0x2bc/0x3a0 The COW inode is only needed to locate the on-disk block, and that block address is already resolved into @blkaddr by prepare_atomic_write_begin() via __find_data_block(cow_inode, ...); f2fs_submit_page_read() then reads from that physical @blkaddr directly, so the inode argument only selects the post-read crypto context, not which block is fetched. Reading with @inode therefore returns the same (latest, not-yet-committed) COW data, while making both the fs-layer decryption decision and the inline crypto path use the correct (original inode's) key. With the COW inode no longer used at the read site, the use_cow flag has no remaining consumer; drop it from f2fs_write_begin() and prepare_atomic_write_begin().

In the Linux kernel, the following vulnerability has been resolved: bpf: use kvfree() for replaced sysctl write buffer proc_sys_call_handler() allocates its temporary sysctl buffer with kvzalloc() and passes it to __cgroup_bpf_run_filter_sysctl(). Since kvzalloc() may fall back to vmalloc() for large allocations, freeing that buffer with kfree() is wrong and can corrupt memory. Use kvfree() to safely handle both kmalloc and kvzalloc()/vmalloc allocations. The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. Manual inspection confirms that the bug is still present in v7.1-rc5. Reproduced the bug based on v7.1-rc4 in a QEMU x86_64 guest booted with KASAN and CONFIG_FAILSLAB enabled. To exercise the replacement path, the test tree also included the accompanying fix for the stale ret == 1 check in __cgroup_bpf_run_filter_sysctl(). The reproducer confines failslab injections to the proc_sys_call_handler() range, uses stacktrace-depth=32, and injects fail-nth=1 while writing 8191 bytes to /proc/sys/kernel/domainname from a task in the target cgroup. Under that setup, fail-nth=1 triggered the fault: BUG: unable to handle page fault for address: ffffeb0200024d48 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 SMP KASAN NOPTI CPU: 2 UID: 0 PID: 209 Comm: repro_proc_sys_ Not tainted 7.1.0-rc4-00686-g97625979a5d4 PREEMPT(lazy) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:kfree+0x6e/0x510 ... Call Trace: <TASK> ? __cgroup_bpf_run_filter_sysctl+0x626/0xc30 __cgroup_bpf_run_filter_sysctl+0x74d/0xc30 ? __pfx___cgroup_bpf_run_filter_sysctl+0x10/0x10 ? srso_return_thunk+0x5/0x5f ? __kvmalloc_node_noprof+0x345/0x870 ? proc_sys_call_handler+0x250/0x480 ? srso_return_thunk+0x5/0x5f proc_sys_call_handler+0x3a2/0x480 ? __pfx_proc_sys_call_handler+0x10/0x10 ? srso_return_thunk+0x5/0x5f ? selinux_file_permission+0x39f/0x500 ? srso_return_thunk+0x5/0x5f ? lock_is_held_type+0x9e/0x120 vfs_write+0x98e/0x1000 ... </TASK> With this fix applied on top of the same test setup, rerunning the reproducer with fail-nth=1 yields no corresponding Oops reports.

In the Linux kernel, the following vulnerability has been resolved: exfat: fix potential use-after-free in exfat_find_dir_entry() In exfat_find_dir_entry(), the buffer_head obtained from exfat_get_dentry() is released with brelse(bh) before the fall-through TYPE_EXTEND branch reads the directory entry through ep (which points into bh->b_data): brelse(bh); if (entry_type == TYPE_EXTEND) { ... len = exfat_extract_uni_name(ep, entry_uniname); ... } After brelse() drops our reference, nothing guarantees that the underlying page backing bh->b_data remains valid for the subsequent exfat_extract_uni_name() read. This is the same pattern fixed in commit fc961522ddbd ("exfat: Fix potential use after free in exfat_load_upcase_table()"). Move brelse(bh) so it runs after ep is no longer dereferenced on each branch. Confirmed on QEMU x86_64 with CONFIG_KASAN=y + CONFIG_DEBUG_PAGEALLOC=y + CONFIG_PAGE_POISONING=y on linux-next, using a crafted exFAT image (long filename with same-hash collisions forcing the TYPE_EXTEND path). With a debug-only invalidate_bdev() inserted between brelse(bh) and the ep read to make the stale-deref window deterministic, the unpatched kernel faults: BUG: KASAN: use-after-free in exfat_find_dir_entry+0x133b/0x15a0 BUG: unable to handle page fault for address: ffff88801a5fa0c2 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI RIP: 0010:exfat_find_dir_entry+0x1188/0x15a0 With this patch applied, the same instrumented harness completes cleanly under the same sanitizer stack. I have not reproduced a crash on an uninstrumented kernel under ordinary reclaim; the instrumented A/B establishes the lifetime violation and that the patch closes it, not an unaided triggerability claim.

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level When recovering hugepages in the shadow MMU, verify that the base gfn of the shadow page is actually contained within the target memslot, *before* querying the max mapping level given the shadow page's gfn. Failure to pre-check the validity of the gfn can lead to an out-of-bounds access to the slot's lpage_info (which typically manifests as a host #PF because the lpage_info is vmalloc'd) if the guest creates a hugepage mapping (in its PTEs) that extends "below" the bounds of a memslot. When faulting in memory for a guest, and the size of the guest mapping is greater than KVM's (current) max mapping, then KVM will create a "direct" shadow page (direct in that there are no gPTEs to shadow, and so the target gfn is a direct calculation given the base gfn of the shadow page). The hugepage recovery flow looks for such direct shadow pages, as forcing 4KiB mappings when dirty logging generates the guest > host mapping size case. When the 4KiB restriction is lifted, then KVM can replace the shadow page with a hugepage. But if KVM originally used a smaller mapping than the guest because the range of memory covered by the guest hugepage exceeds the bounds of a memslot, then KVM will link a direct shadow page with a gfn that is outside the bounds of the memslot being used to fault in memory. The rmap entry added for the leaf mapping is correct and within bounds, but the gfn of the leaf SPTE's parent shadow page will be out of bounds. BUG: unable to handle page fault for address: ffffc90000806ffc #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 100000067 P4D 100000067 PUD 1002a7067 PMD 10612f067 PTE 0 Oops: Oops: 0000 [#1] SMP CPU: 13 UID: 1000 PID: 757 Comm: mmu_stress_test Not tainted 7.1.0-rc1-48ce1e26eace-x86_pir_to_irr_comments-vm #341 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_mmu_max_mapping_level+0x79/0x2b0 [kvm] Call Trace: <TASK> kvm_mmu_recover_huge_pages+0x21b/0x320 [kvm] kvm_set_memslot+0x1ee/0x590 [kvm] kvm_set_memory_region.part.0+0x3a1/0x4d0 [kvm] kvm_vm_ioctl+0x9bf/0x15d0 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb7/0xbb0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f21c0f1a9bf </TASK> Don't bother pre-checking the bounds of the potential hugepage, i.e. don't check that e.g. sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level + 1) is also within the memslot, as the checks performed by kvm_mmu_max_mapping_level() are a superset of the basic bounds checks. I.e. pre-checking the full range would be a dubious micro-optimization.

In the Linux kernel, the following vulnerability has been resolved: crypto: nx - fix nx_crypto_ctx_exit argument nx_crypto_ctx_shash_exit calls nx_crypto_ctx_exit with crypto_shash_ctx(...) but crypto_shash_ctx gives a nx_crypto_ctx *, not a crypto_tfm *. Fix the type in nx_crypto_ctx_exit and drop the bogus crypto_tfm_ctx call. This fixes the following oops: BUG: Unable to handle kernel data access at 0xc0403effffffffc8 Faulting instruction address: 0xc000000000396cb4 Oops: Kernel access of bad area, sig: 11 [#15] Call Trace: nx_crypto_ctx_shash_exit+0x24/0x60 crypto_shash_exit_tfm+0x28/0x40 crypto_destroy_tfm+0x98/0x140 crypto_exit_ahash_using_shash+0x20/0x40 crypto_destroy_tfm+0x98/0x140 hash_release+0x1c/0x30 alg_sock_destruct+0x38/0x60 __sk_destruct+0x48/0x2b0 af_alg_release+0x58/0xb0 __sock_release+0x68/0x150 sock_close+0x20/0x40 __fput+0x110/0x3a0 sys_close+0x48/0xa0 system_call_exception+0x140/0x2d0 system_call_common+0xf4/0x258 .. which came from hardlink(1) opportunistically using AF_ALG. The same problem exists with nx_crypto_ctx_skcipher_exit getting a context it wasn't expecting, but apparently nobody hit that for years.

In the Linux kernel, the following vulnerability has been resolved: gfs2: fix use-after-free in gfs2_qd_dealloc gfs2_qd_dealloc(), called as an RCU callback from gfs2_qd_dispose(), accesses the superblock object sdp through qd->qd_sbd after freeing qd. It does so to decrement sd_quota_count and wake up sd_kill_wait. However, by the time the RCU callback runs, gfs2_put_super() may have already freed sdp via free_sbd(). This can happen when gfs2_quota_cleanup() is called during unmount: it disposes of quota objects via call_rcu() and then waits on sd_kill_wait with a 60-second timeout. If the timeout expires, or if gfs2_gl_hash_clear() triggers additional qd_put() calls that schedule more RCU callbacks after the wait completes, gfs2_put_super() will proceed to free the superblock while RCU callbacks referencing it are still pending. Add an rcu_barrier() before free_sbd() in gfs2_put_super() to ensure all pending RCU callbacks (including gfs2_qd_dealloc) have completed before the superblock is freed.

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix UAF in __blkcg_rstat_flush() When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkg's __blkcg_rstat_flush() removes another blkg's iostat entries via llist_del_all(). The second blkg sees an empty list and proceeds to free itself while the first is still iterating over its entries. Move the flush from __blkg_release() (RCU callback) to blkg_release() (before call_rcu). This ensures the RCU grace period waits for any concurrent flush's rcu_read_lock() section to complete before freeing.

In the Linux kernel, the following vulnerability has been resolved: tipc: fix slab-use-after-free Read in tipc_aead_decrypt_done tipc_aead_decrypt() goes straight from tipc_bearer_hold(b) to crypto_aead_decrypt(req) without taking a reference on the netns, unlike the encrypt path. When crypto_aead_decrypt() is offloaded asynchronously (e.g. the SIMD aead wrapper queuing to cryptd), the cryptd worker runs tipc_aead_decrypt_done() later. If the bearer's netns is torn down in the meantime, cleanup_net() -> tipc_exit_net() -> tipc_crypto_stop() frees the per-netns tipc_crypto, and the completion then reads it: tipc_aead_decrypt_done() dereferences aead->crypto->stats and aead->crypto->net, and tipc_crypto_rcv_complete() dereferences aead->crypto->aead[] and the node table -- reading freed memory. Decoded KASAN splat (v7.1-rc7, CONFIG_KASAN_INLINE + TIPC + TIPC_CRYPTO): BUG: KASAN: slab-use-after-free in tipc_aead_decrypt_done (net/tipc/crypto.c:999) Read of size 8 at addr ffff8881056258a8 by task kworker/u16:2/51 Workqueue: events_unbound Call Trace: tipc_aead_decrypt_done (net/tipc/crypto.c:999) process_one_work (kernel/workqueue.c:3314) worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245) Allocated by task 169: __kasan_kmalloc (mm/kasan/common.c:398 mm/kasan/common.c:415) tipc_crypto_start (net/tipc/crypto.c:1502) tipc_init_net (net/tipc/core.c:72) ops_init (net/core/net_namespace.c:137) setup_net (net/core/net_namespace.c:446) copy_net_ns (net/core/net_namespace.c:579) create_new_namespaces (kernel/nsproxy.c:132) __x64_sys_unshare (kernel/fork.c:3316) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Freed by task 8: kfree (mm/slub.c:6566) tipc_exit_net (net/tipc/core.c:119) cleanup_net (net/core/net_namespace.c:704) process_one_work (kernel/workqueue.c:3314) kthread (kernel/kthread.c:436) This is the same class of bug that commit e279024617134 ("net/tipc: fix slab-use-after-free Read in tipc_aead_encrypt_done") fixed for the encrypt side. The encrypt path takes maybe_get_net(aead->crypto->net) before crypto_aead_encrypt() and drops it with put_net() on the synchronous return paths and in tipc_aead_encrypt_done(); the -EINPROGRESS/-EBUSY return keeps the reference for the async callback to release. The decrypt path was left without the equivalent guard. Mirror the encrypt-side fix on the decrypt path: take a net reference before crypto_aead_decrypt() (failing with -ENODEV and the matching bearer put if it cannot be acquired), keep it across the -EINPROGRESS/-EBUSY async return, and drop it with put_net() on the synchronous success/error return and at the end of tipc_aead_decrypt_done(). Reproduced under KASAN on v7.1-rc7: a UDP bearer with a cluster key is flooded with crafted encrypted frames from an unknown peer (driving the cluster-key decrypt path) while the bearer's netns is repeatedly torn down. The completion must run asynchronously to outlive tipc_crypto_stop(); on x86 the stock aesni gcm(aes) now decrypts synchronously, so the async path was exercised via cryptd offload. The unguarded aead->crypto dereference in tipc_aead_decrypt_done() is the unpatched upstream path; tipc_aead_decrypt() still lacks maybe_get_net(aead->crypto->net), so the completion can outlive the free on any config where crypto_aead_decrypt() goes async. Found by 0sec automated security-research tooling (https://0sec.ai).

In the Linux kernel, the following vulnerability has been resolved: pNFS: Fix use-after-free in pnfs_update_layout() When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(), the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds, pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(), which still references 'lo'. This results in a use-after-free when the tracepoint accesses lo's fields. Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo).

In the Linux kernel, the following vulnerability has been resolved: sched/mmcid: Fix OOB clear_bit when CID is MM_CID_UNSET in fixup path In mm_cid_fixup_cpus_to_tasks(), when rq->curr has the target mm and mm_cid.active is set, the CID is checked with cid_in_transit() before setting the transition bit. In per-CPU mode a newly forked or exec'd task can be running with mm_cid.cid == MM_CID_UNSET because CIDs are assigned lazily on schedule-in. With cid_in_transit() the guard passes for MM_CID_UNSET (no transit bit), converts it to MM_CID_UNSET | MM_CID_TRANSIT and stores it back; later mm_cid_schedout() feeds this to clear_bit() with MM_CID_UNSET as the bit number, triggering an out-of-bounds write. Symptoms: this is genuine memory corruption, but a bounded out-of-bounds write, not an arbitrary one. MM_CID_UNSET is the fixed sentinel BIT(31), so once the bad value reaches mm_cid_schedout() the cid_from_transit_cid() strip leaves MM_CID_UNSET, which fails the "cid < max_cids" convergence test and falls into mm_drop_cid() -> clear_bit(MM_CID_UNSET, mm_cidmask(mm)). The cid bitmap is embedded in the mm_struct slab object (after cpu_bitmap and mm_cpus_allowed) and is only num_possible_cpus() bits wide, so clearing bit 31 is a deterministic OOB bit-clear at a fixed offset of 2^31 / 8 == 256 MiB past the bitmap base. The address is not attacker-influenced (fixed sentinel -> fixed offset) and the op only clears a single bit; what sits 256 MiB further along the direct map is whatever kernel object happens to live there, so this corrupts one bit of unpredictable kernel memory -- it is not an arbitrary-address or arbitrary-value write. It triggers only in per-CPU CID mode, when a CPU is running an active task of the target mm whose cid is still MM_CID_UNSET -- the fork()/execve() window before that task's next schedule-in assigns it a real CID -- and a per-CPU -> per-task fixup walks over it (the mode fallback driven by a thread exit, sched_mm_cid_exit(), or by the deferred max_cids recompute in mm_cid_work_fn()). In practice syzkaller surfaced it as a KASAN use-after-free reported in __schedule -> mm_cid_switch_to, where the offending clear_bit() is inlined via mm_cid_schedout() -> mm_drop_cid(). Guard the transition-bit assignment against MM_CID_UNSET, in addition to the existing cid_in_transit() check, so the bit is only set on a genuine task-owned CID. A CPU-owned (MM_CID_ONCPU) CID of a running active task is handled by the cid_on_cpu(pcp->cid) branch above and never reaches this path, so excluding MM_CID_UNSET (and the already-transitioning case) is sufficient.

In the Linux kernel, the following vulnerability has been resolved: irqchip/imgpdc: Fix resource leak, add missing chained handler cleanup on remove The driver allocates domain generic chips using irq_alloc_domain_generic_chips() during probe and sets up chained handlers using irq_set_chained_handler_and_data(). However, on driver removal, the generic chips are not freed and the chained handlers are not removed. The generic chips remain on the global gc_list and may later be accessed by generic interrupt chip suspend, resume, or shutdown callbacks after the driver has been removed, potentially resulting in a use-after-free and kernel crash. The chained handlers that were installed in probe for peripheral and syswake interrupts are also left dangling, which can lead to spurious interrupts accessing freed memory. Fix these issues by: - Setting IRQ_DOMAIN_FLAG_DESTROY_GC flag in domain->flags, so the core code automatically removes generic chips when irq_domain_remove() is called - Clearing all chained handlers with NULL in pdc_intc_remove()

In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject oversized group bitmap descriptors ocfs2_validate_gd_parent() only bounds bg_bits against the parent allocator's chain geometry. A malicious descriptor can still claim a bg_size/bg_bits pair that exceeds the bitmap bytes that physically fit in the group descriptor block, so later bitmap scans and bit updates can run past bg_bitmap. Add a physical-cap check based on ocfs2_group_bitmap_size() for the parent allocator type and reject descriptors whose bg_size or bg_bits exceed that capacity. Keep the existing chain geometry check so both the on-disk bitmap layout and the allocator metadata must agree before the descriptor is used. Validation reproduced this kernel report: KASAN use-after-free in _find_next_bit+0x7f/0xc0 Read of size 8 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xd0/0x630 (?:?) _find_next_bit+0x7f/0xc0 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x188/0x2f0 (?:?) kasan_report+0xe4/0x120 (?:?) ocfs2_find_max_contig_free_bits+0x35/0x70 (fs/ocfs2/suballoc.c:1375) ocfs2_block_group_set_bits+0x472/0x4b0 (fs/ocfs2/suballoc.c:1457) ocfs2_cluster_group_search+0x16b/0x440 (fs/ocfs2/suballoc.c:86) ocfs2_bg_discontig_fix_result+0x1ef/0x230 (fs/ocfs2/suballoc.c:1786) ocfs2_search_chain+0x8f8/0x10a0 (fs/ocfs2/suballoc.c:1886) get_page_from_freelist+0x70e/0x2370 (?:?) lock_release+0xc6/0x290 (?:?) do_raw_spin_unlock+0x9a/0x100 (?:?) kasan_unpoison+0x27/0x60 (?:?) __bfs+0x147/0x240 (?:?) get_page_from_freelist+0x83d/0x2370 (?:?) ocfs2_claim_suballoc_bits+0x38c/0xe70 (fs/ocfs2/suballoc.c:96) sched_domains_numa_masks_clear+0x70/0xd0 (?:?) check_irq_usage+0xe8/0xb70 (?:?) __ocfs2_claim_clusters+0x18d/0x4c0 (fs/ocfs2/suballoc.c:2497) check_path+0x24/0x50 (?:?) rcu_is_watching+0x20/0x50 (?:?) check_prev_add+0xfd/0xd00 (?:?) ocfs2_add_clusters_in_btree+0x17d/0x810 (fs/ocfs2/suballoc.c:?) __folio_batch_add_and_move+0x1f5/0x3d0 (?:?) ocfs2_add_inode_data+0xd9/0x120 (fs/ocfs2/suballoc.c:?) filemap_add_folio+0x105/0x1f0 (?:?) ocfs2_write_begin_nolock+0x29f7/0x2f80 (fs/ocfs2/suballoc.c:3043) ocfs2_read_inode_block+0xb5/0x110 (fs/ocfs2/suballoc.c:?) down_write+0xf5/0x180 (?:?) ocfs2_write_begin+0x180/0x240 (fs/ocfs2/suballoc.c:?) __mark_inode_dirty+0x758/0x9a0 (?:?) inode_to_bdi+0x41/0x90 (?:?) balance_dirty_pages_ratelimited_flags+0xf8/0x1d0 (?:?) generic_perform_write+0x252/0x440 (?:?) mnt_put_write_access_file+0x16/0x70 (?:?) file_update_time_flags+0xe4/0x200 (?:?) ocfs2_file_write_iter+0x80a/0x1320 (fs/ocfs2/suballoc.c:?) lock_acquire+0x184/0x2f0 (?:?) ksys_write+0xd2/0x170 (?:?) apparmor_file_permission+0xf5/0x310 (?:?) read_zero+0x8d/0x140 (?:?) lock_is_held_type+0x8f/0x100 (?:?)

In the Linux kernel, the following vulnerability has been resolved: 9p: avoid putting oldfid in p9_client_walk() error path When p9_client_walk() is called with clone set to false, fid aliases oldfid. If the walk subsequently fails after the request has been sent, the error path jumps to clunk_fid, which currently calls p9_fid_put(fid) unconditionally. This drops a reference to oldfid even though ownership of oldfid remains with the caller. If this is the last reference, oldfid can be clunked and destroyed while the caller still expects it to be valid. A later use or put of oldfid can then trigger a use-after-free or refcount underflow. Fix this by only putting fid in the clunk_fid error path when it does not alias oldfid, matching the existing guard in the error path below. This can be triggered when a multi-component walk is split into multiple p9_client_walk() calls and a later non-cloning walk fails. A reproducer and refcount warning logs are available on request.

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path In sev_dbg_crypt(), the per-iteration transfer length is bounded by the source page offset (PAGE_SIZE - s_off) but not by the destination page offset (PAGE_SIZE - d_off). When d_off > s_off, the encrypt path (__sev_dbg_encrypt_user) performs a read-modify-write using a single-page intermediate buffer (dst_tpage): 1. __sev_dbg_decrypt() expands the size to round_up(len + (d_off & 15), 16) before issuing the PSP command. If len + (d_off & 15) > PAGE_SIZE, the PSP writes beyond the end of the 4096-byte dst_tpage allocation. 2. The subsequent memcpy()/copy_from_user() into page_address(dst_tpage) + (d_off & 15) of 'len' bytes overflows by up to 15 bytes under the same condition. Trigger example: s_off = 0, d_off = 1, debug.len = PAGE_SIZE - the PSP is instructed to write round_up(4097, 16) = 4112 bytes to a 4096-byte buffer. Fix by also bounding len by (PAGE_SIZE - d_off), the same check that sev_send_update_data() already performs for its single-page guest region. ================================================================== BUG: KASAN: slab-use-after-free in sev_dbg_crypt+0x993/0xd10 [kvm_amd] Write of size 4095 at addr ff110062293bb009 by task sev_dbg_test/228214 CPU: 96 UID: 0 PID: 228214 Comm: sev_dbg_test Tainted: G U W 7.0.0-smp--5ce9b0c48211-dbg #156 PREEMPTLAZY Tainted: [U]=USER, [W]=WARN Hardware name: Google Astoria/astoria, BIOS 0.20250817.1-0 08/25/2025 Call Trace: <TASK> dump_stack_lvl+0x54/0x70 print_report+0xbc/0x260 kasan_report+0xa2/0xd0 kasan_check_range+0x25f/0x2c0 __asan_memcpy+0x40/0x70 sev_dbg_crypt+0x993/0xd10 [kvm_amd] sev_mem_enc_ioctl+0x33c/0x450 [kvm_amd] kvm_vm_ioctl+0x65d/0x6d0 [kvm] __se_sys_ioctl+0xb2/0x100 do_syscall_64+0xe8/0x870 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x7fe72b6a0 pfn:0x62293bb memcg:ff11000112827d82 flags: 0x1400000000000000(node=1|zone=1) raw: 1400000000000000 0000000000000000 dead000000000122 0000000000000000 raw: 00000007fe72b6a0 0000000000000000 00000001ffffffff ff11000112827d82 page dumped because: kasan: bad access detected Memory state around the buggy address: ff110062293bbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff110062293bbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ff110062293bc000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ff110062293bc080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ff110062293bc100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== Disabling lock debugging due to kernel taint [sean: add sample KASAN splat, Fixes, and stable@]

In the Linux kernel, the following vulnerability has been resolved: ntfs: serialize volume label accesses Protect vol->volume_label with a mutex and snaphost the label before copy_to_user. This prevent a use-after-free when FS_IOC_SETFSLABEL replaces the vol->volume_label and FS_IOC_GETTSLABEL reads it concurrently.

In the Linux kernel, the following vulnerability has been resolved: fbdev: omap2: fix use-after-free in omapfb_mmap omapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that can lead to use-after-free: The fb_mmap() entry point holds mm_lock but not lock (fb_info->lock), while ioctl handlers like OMAPFB_SETUP_PLANE hold lock but not mm_lock. This allows concurrent execution. In omapfb_mmap(): 1. rg = omapfb_get_mem_region(ofbi->region); // Get old region ref 2. start = omapfb_get_region_paddr(ofbi); // Read from NEW region 3. len = fix->smem_len; // Read from NEW region 4. vm_iomap_memory(vma, start, len); // Map NEW region memory 5. atomic_inc(&rg->map_count); // Increment OLD region! Concurrently, OMAPFB_SETUP_PLANE can: - Reassign ofbi->region = new_rg - Update fix->smem_len - OMAPFB_SETUP_MEM then checks NEW region's map_count (0!) and frees it This leaves userspace with a mapping to freed physical memory. The fix is to read all required values (start, len) from the same region reference (rg) that will have its map_count incremented, preventing the region from being freed while still mapped.

In the Linux kernel, the following vulnerability has been resolved: NFSD: Fix SECINFO_NO_NAME decode error cleanup nfsd4_decode_secinfo_no_name() currently initializes sin_exp after decoding sin_style. If the XDR stream is truncated, the decoder returns nfserr_bad_xdr before sin_exp is initialized. Since commit 3fdc54646234 ("NFSD: Reduce amount of struct nfsd4_compoundargs that needs clearing"), the inline iops array is not cleared between RPC calls. A failed SECINFO_NO_NAME decode can therefore leave sin_exp holding stale union contents from a previous operation. The error response path still invokes nfsd4_secinfo_no_name_release(), which calls exp_put() on a non-NULL sin_exp. Initialize sin_exp before the first failable decode step, matching nfsd4_decode_secinfo().

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix posix_acl leak on SETACL decode failure nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each call nfs_stream_decode_acl() twice, first for NFS_ACL and then for NFS_DFACL. Each successful call transfers ownership of a freshly allocated posix_acl into argp->acl_access or argp->acl_default. If the first call succeeds but the second fails, the decoder returns false and argp->acl_access is left dangling. ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle. Both only call fh_put() and have no knowledge of the ACL fields on argp. The posix_acl_release() pairs sat at the out: labels inside nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process() skips pc_func when pc_decode returns false, so that cleanup is unreachable on decode failure: svc_process_common() pc_decode() /* decode_setaclargs: false */ /* pc_func skipped */ pc_release() /* fh_put only -- ACLs leaked */ The orphaned posix_acl is leaked for the lifetime of the server. Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(), which release both argp->acl_access and argp->acl_default in addition to fh_put(), and wiring them as pc_release for their respective SETACL procedures. pc_release runs on every path svc_process() takes after decode, including decode failure, so the posix_acl_release() pairs are removed from the proc functions' out: labels to keep ownership in one place. This matches the existing release_getacl() pattern used by the sibling GETACL procedures.

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix posix_acl leak and ignored error in nfsd4_create_file nfsd4_create_file() has two bugs in its ACL handling: The return value of nfsd4_acl_to_attr() is silently discarded. When the NFSv4-to-POSIX ACL conversion fails (e.g., -EINVAL for unsupported ACE types), the file is created without any ACL and the client receives NFS4_OK. This violates RFC 7530/8881 which require the server to reject unsupported attributes on CREATE. When start_creating() fails after ACL attributes have been populated in attrs (either via nfsd4_acl_to_attr or via ownership transfer from open->op_dpacl/op_pacl), the function jumps to out_write which skips nfsd_attrs_free(). The posix_acl allocations are leaked. A client can trigger this repeatedly with OPEN(CREATE), ACL attributes, and an invalid filename (e.g., longer than NAME_MAX). Fix both by capturing the nfsd4_acl_to_attr() return value and by changing the early error paths to jump to out instead of out_write. Initialize child to ERR_PTR(-EINVAL) so that end_creating() is safe to call even if start_creating() was never reached.

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix dead ACL conflict guard in nfsd4_create nfsd4_create() steals create->cr_dpacl/cr_pacl into the local nfsd_attrs via the designated initializer, then immediately sets the source pointers to NULL. The subsequent conflict guard tests the already-nilled source fields, making it permanently dead code: if (create->cr_acl) { if (create->cr_dpacl || create->cr_pacl) /* always false */ When a client encodes both FATTR4_WORD0_ACL and FATTR4_WORD2_POSIX_{DEFAULT,ACCESS}_ACL in the same CREATE fattr bitmap, nfsd4_acl_to_attr() overwrites attrs.na_pacl/na_dpacl without releasing the originals, leaking two posix_acl slab objects per request. Repeated requests cause unbounded slab exhaustion. Fix by checking attrs.na_dpacl/na_pacl (the stolen values) instead of the nilled create->cr_dpacl/cr_pacl, matching the correct pattern already used in nfsd4_setattr().

In the Linux kernel, the following vulnerability has been resolved: nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race When find_or_alloc_open_stateowner() encounters an unconfirmed owner, it calls release_openowner() and sets oo = NULL. Control then falls through past the `if (oo)` guard -- which would have freed any pre-allocated `new` -- and unconditionally executes `new = alloc_stateowner(...)`. If `new` was already allocated on a prior iteration, the pointer is silently overwritten and the previous allocation (slab object + owner name buffer) is leaked. This requires a race: two NFSv4.0 OPEN threads with the same owner string, where a concurrent thread inserts a new unconfirmed owner into the hash between retry iterations. The window is narrow but repeatable under adversarial conditions. Fix by adding `goto retry` after `oo = NULL` so the already-allocated `new` is reused on the next iteration rather than overwritten.

In the Linux kernel, the following vulnerability has been resolved: NFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr nfs4_decode_mp_ds_addr() decodes the r_netid and r_addr opaques of a netaddr4 from a GETDEVICEINFO multipath-DS body, then immediately calls strrchr(buf, '.') to locate the port separator. Both decodes use xdr_stream_decode_string_dup(), and the current code checks only "nlen < 0" / "rlen < 0" before dereferencing the returned string. When the on-wire opaque has length zero, xdr_stream_decode_opaque_inline() returns 0 and xdr_stream_decode_string_dup() falls through to its "*str = NULL; return ret" tail, leaving buf NULL with a return value of 0. The "< 0" check does not catch this, and the next line is strrchr(NULL, '.'), a kernel NULL pointer dereference reachable from any pNFS-flexfile client mounted against a malicious or compromised metadata server. Reject the zero-length cases explicitly so the decoder fails with -EBADMSG (treated as a malformed GETDEVICEINFO body) instead of panicking the client.

In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: fix use-after-free of key in del_async path In tcp_ao_delete_key(), the del_async path skips the current_key and rnext_key validity checks present in the synchronous path, assuming these pointers are always NULL on LISTEN sockets. However, if a key was added with set_current=1/set_rnext=1 while the socket was in CLOSE state, current_key and rnext_key will be non-NULL after listen() transitions the socket to LISTEN. When such a key is deleted with del_async=1, hlist_del_rcu() and call_rcu() free the key without clearing the dangling pointers. After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences current_key->sndid and rnext_key->rcvid from freed slab memory. Clear current_key and rnext_key in the del_async path when they reference the key being deleted.

In the Linux kernel, the following vulnerability has been resolved: fuse: re-lock request before replacing page cache folio fuse_try_move_folio() unlocks the request on entry but does not re-lock it on the success path. This means fuse_chan_abort() can end the request and free the fuse_io_args (eg fuse_readpages_end()) while the subsequent copy chain logic after fuse_try_move_folio() accesses the fuse_io_args, leading to use-after-free issues. Fix this by calling lock_request() before replace_page_cache_folio(). This ensures the request is locked on the success path which will prevent the fuse_io_args from being freed while the later copying logic runs, and also ensures that the ap->folios[i]->mapping is never null since ap->folios[i] will always point to the newfolio after replace_page_cache_folio().

In the Linux kernel, the following vulnerability has been resolved: iio: light: veml6075: add bounds check to veml6075_it_ms index veml6075_it_ms has 5 elements but VEML6075_CONF_IT can yield values 0-7. If it returns a value >= 5, this causes an out-of-bounds array access. Add a bounds check and return -EINVAL if the index is out of range. The problem values are reserved so should never be read from the register. Hence this is hardening against fault device, missprogramming or bus corruption.

In the Linux kernel, the following vulnerability has been resolved: iio: adc: ti-ads1298: add bounds check to pga_settings index ads1298_pga_settings has 7 elements but ADS1298_MASK_CH_PGA can yield values 0-7. If it yields a value >= 7, this causes an out-of-bounds array access. Add a bounds check and return -EINVAL if the index is out of range. Note that the remaining value b111 is reserved so should not be seen in a correctly functioning system.

In the Linux kernel, the following vulnerability has been resolved: vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write A KASAN null-ptr-deref was observed in vcs_notifier(): BUG: KASAN: null-ptr-deref in vcs_notifier+0x98/0x130 Read of size 2 at addr qmp_cmd_name: qmp_capabilities, arguments: {} The issue is a race condition in vcs_write(). When the console_lock is temporarily dropped (to copy data from userspace), the vc_data pointer obtained from vcs_vc() may become stale. After re-acquiring the lock, vcs_vc() is called again to re-validate the pointer. If the vc has been deallocated in the meantime, vcs_vc() returns NULL, and the while loop breaks (with written > 0). However, after the loop, vcs_scr_updated(vc) is still called with the now-NULL vc pointer, leading to a null pointer dereference in the notifier chain (vcs_notifier dereferences param->vc). Fix this by adding a NULL check for vc before calling vcs_scr_updated().

In the Linux kernel, the following vulnerability has been resolved: serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails dw8250_probe() registers the 8250 port via serial8250_register_8250_port() and then, if the device has a clock, registers a clock notifier. If clk_notifier_register() fails, probe returns the error but leaves the 8250 port registered. The matching serial8250_unregister_port() lives in dw8250_remove(), which is not called when probe fails, so the port slot stays occupied until the device is rebound or the system is rebooted. The devm-allocated driver data is freed while the port still references it (via the saved private_data and serial_in/serial_out callbacks), so any access to that port slot before a rebind is a use-after-free hazard. Unregister the port on the clk_notifier_register() error path.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: reject non-VALID session in compound request branch smb2_check_user_session() takes a shortcut for any operation that is not the first in a COMPOUND request: it reuses work->sess (the session bound by the first operation) and validates only the SessionId, then returns "valid". It never re-checks work->sess->state == SMB2_SESSION_VALID, and a SessionId of 0xFFFFFFFFFFFFFFFF (ULLONG_MAX, the MS-SMB2 related-operation value) skips even the id comparison. The standalone path (ksmbd_session_lookup_all() plus the SESSION_SETUP state machine) does enforce the VALID state; the compound branch bypasses all of it. A SESSION_SETUP carrying only an NTLM Type-1 (NtLmNegotiate) blob publishes a fresh SMB2_SESSION_IN_PROGRESS session whose sess->user is still NULL (->user is assigned later, by ntlm_authenticate()). Used as operation 1 of a COMPOUND with operation 2 = TREE_CONNECT (related, SessionId=ULLONG_MAX, \\host\IPC$), the tree-connect then runs on that IN_PROGRESS session and reaches ksmbd_ipc_tree_connect_request(), which dereferences user_name(sess->user) with sess->user == NULL (transport_ipc.c:687/701/704) -> remote NULL-pointer dereference and a kernel Oops that wedges the ksmbd worker for all clients. Reject any non-first compound operation that lands on a session which is not SMB2_SESSION_VALID, mirroring the validity the standalone lookup path enforces. SESSION_SETUP itself legitimately runs on an IN_PROGRESS session, but it is never carried as a non-first compound operation, so multi-leg authentication is unaffected by this check.

In the Linux kernel, the following vulnerability has been resolved: media: vidtv: fix NULL pointer dereference in vidtv_mux_push_si syzbot reported a general protection fault in vidtv_psi_ts_psi_write_into [1]. vidtv_mux_get_pid_ctx() can return NULL, but vidtv_mux_push_si() does not check for this before dereferencing the returned pointer to access the continuity counter. This leads to a general protection fault when accessing a near-NULL address. The root cause is that vidtv_mux_pid_ctx_init() does not check the return value of vidtv_mux_create_pid_ctx_once() for PMT section PIDs. If the allocation fails, the PID context is never created, but init returns success. The subsequent vidtv_mux_push_si() call then gets NULL from vidtv_mux_get_pid_ctx() and crashes. Fix both the root cause (add error check in vidtv_mux_pid_ctx_init for PMT PIDs) and add defensive NULL checks in vidtv_mux_push_si for all vidtv_mux_get_pid_ctx() calls. [1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] Workqueue: events vidtv_mux_tick RIP: 0010:vidtv_psi_ts_psi_write_into+0x54a/0xbc0 drivers/media/test-drivers/vidtv/vidtv_psi.c:197 Call Trace: <TASK> vidtv_psi_table_header_write_into drivers/media/test-drivers/vidtv/vidtv_psi.c:799 [inline] vidtv_psi_pmt_write_into+0x3b2/0xa70 drivers/media/test-drivers/vidtv/vidtv_psi.c:1231 vidtv_mux_push_si+0x932/0xe80 drivers/media/test-drivers/vidtv/vidtv_mux.c:196 vidtv_mux_tick+0xe9b/0x1480 drivers/media/test-drivers/vidtv/vidtv_mux.c:408

In the Linux kernel, the following vulnerability has been resolved: virtiofs: fix UAF on submount umount iput() called from fuse_release_end() can Oops if the super block has already been destroyed. Normally this is prevented by waiting for num_waiting to go down to zero before commencing with super block shutdown. This only works, however, for the last submount instance, as the wait counter is per connection, not per superblock. Revert to using synchronous release requests for the auto_submounts case, which is virtiofs only at this time.

In the Linux kernel, the following vulnerability has been resolved: media: rzv2h-ivc: Fix concurrent buffer list access The list of buffers (`rzv2h_ivc::buffers.queue`) is protected by a spinlock (`rzv2h_ivc::buffers.lock`). However, in `rzv2h_ivc_transfer_buffer()`, which runs in a separate workqueue, the `list_del()` call is executed without holding the spinlock, which makes it possible for the list to be concurrently modified Fix that by removing a buffer from the list in the lock protected section. [assign ivc->buffers.curr in critical section as reported by Barnabas]