UBUNTU-CVE-2026-99246

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    UBUNTU-CVE-2026-99246

    Published: 3 Nov 2026Last Modified: 6 Nov 2026
    Upstream:
    CVE-2026-99246

    Summary:

    Details: In the Linux kernel, the following vulnerability has been resolved: tipc: protect node reset trace dump with node lock The tipc_node_reset_links trace event asks tipc_node_dump() to walk the node's link entries. Unlike the other node events that request link data, this event runs without the node lock. This permits bearer teardown to free a link while the trace callback is dumping it: CPU 0 CPU 1 trace_tipc_node_reset_links() tipc_node_dump() l = n->links[0].link tipc_node_write_lock() kfree(l) n->links[0].link = NULL tipc_node_write_unlock() tipc_link_dump(l) tipc_link_dump() then dereferences the stale pointer. KASAN reported: BUG: KASAN: slab-use-after-free in tipc_link_dump Read of size 4 by task poc/115 Call Trace: tipc_link_dump+0x10cb/0x16b0 tipc_node_dump+0x4bb/0x740 trace_event_raw_event_tipc_node_class+0x258/0x360 tipc_node_reset_links+0x14d/0x1a0 tipc_rcv+0x13f5/0x3030 tipc_udp_recv+0x4e3/0x670 Allocated by task 0: tipc_link_create+0x1e1/0x1020 tipc_node_check_dest+0x7d2/0x11a0 tipc_disc_rcv+0xdbf/0x1430 Freed by task 89: kfree+0x131/0x3c0 tipc_node_link_down+0x267/0x4b0 tipc_node_delete_links+0xec/0x160 bearer_disable+0x107/0x260 Take the node write lock around the trace event. This serializes the dump against tipc_node_link_down(delete=true), which frees the link under the same write lock.

    References: https://ubuntu.com/security/CVE-2026-99246, https://www.cve.org/CVERecord?id=CVE-2026-99246, https://git.kernel.org/stable/c/fa8c78c0e49aa11fae116fd841e41aa8f2d68751, https://git.kernel.org/stable/c/dddf197f29ba5e47a476dde82bf542ca2e0d5e5e, https://git.kernel.org/stable/c/b8b7d28dc2b7472ffd1eff3954c38f1976b21a7b, https://git.kernel.org/stable/c/7bb6a35bd6d69019539d8782fb590fd2aa8a3236, https://git.kernel.org/stable/c/6abd93d01b0f495f29201925a5ee8e6a583c4044, https://git.kernel.org/stable/c/a6101d62ccfa153db8c218ce59362b8e0316fd4f, https://git.kernel.org/stable/c/6e492cb98ca69cc1145175e23e22e3b84da7f26d, https://git.kernel.org/stable/c/c8b72ca0918e95f708f67c8b3e69b05290f2b6d2

    Affected packages

    Package

    Name: linux-hwe-edge

    Purl: pkg:deb/ubuntu/linux-hwe-edge?arch=source&distro=xenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    4.8.0-28.30~16.04.1
    4.8.0-30.32~16.04.1
    4.8.0-32.34~16.04.1
    4.8.0-34.36~16.04.1

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    UBUNTU-CVE-2026-99246 | CVE-DB