ipv6: mcast: Fix use-after-free when processing MLD queries_CVE-2026-53275

8.8 / 10

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Description

In the Linux kernel, the following vulnerability has been resolved:

ipv6: mcast: Fix use-after-free when processing MLD queries

When processing an MLD query, a pointer to the multicast group address
is retrieved when initially parsing the packet. This pointer is later
dereferenced without being reloaded despite the fact that the skb header
might have been reallocated following the pskb_may_pull() calls, leading
to a use-after-free [1].

Fix by copying the multicast group address when the packet is initially
parsed.

[1]
BUG: KASAN: slab-use-after-free in __mld_query_work (net/ipv6/mcast.c:1512)
Read of size 8 at addr ffff8881154b8e90 by task kworker/4:1/118

Workqueue: mld mld_query_work
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
print_address_description.constprop.0 (mm/kasan/report.c:378)
print_report (mm/kasan/report.c:482)
kasan_report (mm/kasan/report.c:595)
__mld_query_work (net/ipv6/mcast.c:1512)
mld_query_work (net/ipv6/mcast.c:1563)
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)
</TASK>

[...]

Freed by task 118:
kasan_save_stack (mm/kasan/common.c:57)
kasan_save_track (mm/kasan/common.c:78)
kasan_save_free_info (mm/kasan/generic.c:584)
__kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285)
kfree (./include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6251 mm/slub.c:6566)
pskb_expand_head (net/core/skbuff.c:2335)
__pskb_pull_tail (net/core/skbuff.c:2878 (discriminator 4))
__mld_query_work (net/ipv6/mcast.c:1495 (discriminator 1))
mld_query_work (net/ipv6/mcast.c:1563)
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)

AI Analysis

AI processing failed - no valid JSON found

Basic Information

ID CVE-2026-53275

Source Linux

Published Jun 25, 2026 at 08:39

Modified Jun 28, 2026 at 06:41

Affected Product

Vendor Linux

Product Linux

Version 97300b5fdfe28c6edae926926f9467a27cf5889c

Affected Versions Linux Linux 97300b5fdfe28c6edae926926f9467a27cf5889c
Linux Linux 97300b5fdfe28c6edae926926f9467a27cf5889c
Linux Linux 97300b5fdfe28c6edae926926f9467a27cf5889c
Linux Linux 97300b5fdfe28c6edae926926f9467a27cf5889c
Linux Linux 97300b5fdfe28c6edae926926f9467a27cf5889c
Linux Linux 97300b5fdfe28c6edae926926f9467a27cf5889c
Linux Linux 97300b5fdfe28c6edae926926f9467a27cf5889c
Linux Linux 2.6.15

References

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: Fix use-after-free when processing MLD queries\n\nWhen processing an MLD query, a pointer to the multicast group address\nis retrieved when initially parsing the packet. This pointer is later\ndereferenced without being reloaded despite the fact that the skb header\nmight have been reallocated following the pskb_may_pull() calls, leading\nto a use-after-free [1].\n\nFix by copying the multicast group address when the packet is initially\nparsed.\n\n[1]\nBUG: KASAN: slab-use-after-free in __mld_query_work (net/ipv6/mcast.c:1512)\nRead of size 8 at addr ffff8881154b8e90 by task kworker/4:1/118\n\nWorkqueue: mld mld_query_work\nCall Trace:\n<TASK>\ndump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)\nprint_address_description.constprop.0 (mm/kasan/report.c:378)\nprint_report (mm/kasan/report.c:482)\nkasan_report (mm/kasan/report.c:595)\n__mld_query_work (net/ipv6/mcast.c:1512)\nmld_query_work (net/ipv6/mcast.c:1563)\nprocess_one_work (kernel/workqueue.c:3314)\nworker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)\nkthread (kernel/kthread.c:436)\nret_from_fork (arch/x86/kernel/process.c:158)\nret_from_fork_asm (arch/x86/entry/entry_64.S:245)\n</TASK>\n\n[...]\n\nFreed by task 118:\nkasan_save_stack (mm/kasan/common.c:57)\nkasan_save_track (mm/kasan/common.c:78)\nkasan_save_free_info (mm/kasan/generic.c:584)\n__kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285)\nkfree (./include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6251 mm/slub.c:6566)\npskb_expand_head (net/core/skbuff.c:2335)\n__pskb_pull_tail (net/core/skbuff.c:2878 (discriminator 4))\n__mld_query_work (net/ipv6/mcast.c:1495 (discriminator 1))\nmld_query_work (net/ipv6/mcast.c:1563)\nprocess_one_work (kernel/workqueue.c:3314)\nworker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)\nkthread (kernel/kthread.c:436)\nret_from_fork (arch/x86/kernel/process.c:158)\nret_from_fork_asm (arch/x86/entry/entry_64.S:245)",
    "published": "2026-06-25T08:39:59.115Z",
    "modified": "2026-06-28T06:41:17.484Z",
    "type": "cve",
    "title": "ipv6: mcast: Fix use-after-free when processing MLD queries",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/1354271c89d0e5fbf8b3d94097ff0216695209c7\nhttps://git.kernel.org/stable/c/53baa63a4183291574483f89583dbef13677a2c4\nhttps://git.kernel.org/stable/c/2a613bf497029d555a7428406aa8cdb84a503cea\nhttps://git.kernel.org/stable/c/b2eb8886200b907fc71806869620609f0f4cacb0\nhttps://git.kernel.org/stable/c/4203806f700bb44ea0b05d484d9d40044b47fb04\nhttps://git.kernel.org/stable/c/087dbacf897c020f438f780f0a4a8aa73b6d7c5a\nhttps://git.kernel.org/stable/c/791c91dc7a9dfb2457d5e29b8216a6484b9c4b40",
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