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

net: read sk->sk_family once in sk_mc_loop()

syzbot is playing with IPV6_ADDRFORM quite a lot these days,
and managed to hit the WARN_ON_ONCE(1) in sk_mc_loop()

We have many more similar issues to fix.

WARNING: CPU: 1 PID: 1593 at net/core/sock.c:782 sk_mc_loop+0x165/0x260
Modules linked in:
CPU: 1 PID: 1593 Comm: kworker/1:3 Not tainted 6.1.40-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Workqueue: events_power_efficient gc_worker
RIP: 0010:sk_mc_loop+0x165/0x260 net/core/sock.c:782
Code: 34 1b fd 49 81 c7 18 05 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 25 36 6d fd 4d 8b 37 eb 13 e8 db 33 1b fd <0f> 0b b3 01 eb 34 e8 d0 33 1b fd 45 31 f6 49 83 c6 38 4c 89 f0 48
RSP: 0018:ffffc90000388530 EFLAGS: 00010246
RAX: ffffffff846d9b55 RBX: 0000000000000011 RCX: ffff88814f884980
RDX: 0000000000000102 RSI: ffffffff87ae5160 RDI: 0000000000000011
RBP: ffffc90000388550 R08: 0000000000000003 R09: ffffffff846d9a65
R10: 0000000000000002 R11: ffff88814f884980 R12: dffffc0000000000
R13: ffff88810dbee000 R14: 0000000000000010 R15: ffff888150084000
FS: 0000000000000000(0000) GS:ffff8881f6b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000180 CR3: 000000014ee5b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
[<ffffffff8507734f>] ip6_finish_output2+0x33f/0x1ae0 net/ipv6/ip6_output.c:83
[<ffffffff85062766>] __ip6_finish_output net/ipv6/ip6_output.c:200 [inline]
[<ffffffff85062766>] ip6_finish_output+0x6c6/0xb10 net/ipv6/ip6_output.c:211
[<ffffffff85061f8c>] NF_HOOK_COND include/linux/netfilter.h:298 [inline]
[<ffffffff85061f8c>] ip6_output+0x2bc/0x3d0 net/ipv6/ip6_output.c:232
[<ffffffff852071cf>] dst_output include/net/dst.h:444 [inline]
[<ffffffff852071cf>] ip6_local_out+0x10f/0x140 net/ipv6/output_core.c:161
[<ffffffff83618fb4>] ipvlan_process_v6_outbound drivers/net/ipvlan/ipvlan_core.c:483 [inline]
[<ffffffff83618fb4>] ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:529 [inline]
[<ffffffff83618fb4>] ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline]
[<ffffffff83618fb4>] ipvlan_queue_xmit+0x1174/0x1be0 drivers/net/ipvlan/ipvlan_core.c:677
[<ffffffff8361ddd9>] ipvlan_start_xmit+0x49/0x100 drivers/net/ipvlan/ipvlan_main.c:229
[<ffffffff84763fc0>] netdev_start_xmit include/linux/netdevice.h:4925 [inline]
[<ffffffff84763fc0>] xmit_one net/core/dev.c:3644 [inline]
[<ffffffff84763fc0>] dev_hard_start_xmit+0x320/0x980 net/core/dev.c:3660
[<ffffffff8494c650>] sch_direct_xmit+0x2a0/0x9c0 net/sched/sch_generic.c:342
[<ffffffff8494d883>] qdisc_restart net/sched/sch_generic.c:407 [inline]
[<ffffffff8494d883>] __qdisc_run+0xb13/0x1e70 net/sched/sch_generic.c:415
[<ffffffff8478c426>] qdisc_run+0xd6/0x260 include/net/pkt_sched.h:125
[<ffffffff84796eac>] net_tx_action+0x7ac/0x940 net/core/dev.c:5247
[<ffffffff858002bd>] __do_softirq+0x2bd/0x9bd kernel/softirq.c:599
[<ffffffff814c3fe8>] invoke_softirq kernel/softirq.c:430 [inline]
[<ffffffff814c3fe8>] __irq_exit_rcu+0xc8/0x170 kernel/softirq.c:683
[<ffffffff814c3f09>] irq_exit_rcu+0x9/0x20 kernel/softirq.c:695

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00036.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
7ad6848c7e81a603605fad3f3575841aab004eea affected < 7586a66b9c4f1b8a825ea1dfa3a91aad5cc7b89b
7ad6848c7e81a603605fad3f3575841aab004eea affected < e918d0211ffbaf039447334c3460cafee1ce0157
7ad6848c7e81a603605fad3f3575841aab004eea affected < 41f10a4d78fe69d685a3172e6884297f233dcf95
7ad6848c7e81a603605fad3f3575841aab004eea affected < 895dc4c47171a20035cdaa8d74c1c1e97f2fc974
7ad6848c7e81a603605fad3f3575841aab004eea affected < ed4e0adfa407ab65dd73b8862ebf2f308a0349d2
7ad6848c7e81a603605fad3f3575841aab004eea affected < 9036b6342fcdab190d6edce3dd447859c1de90fc
7ad6848c7e81a603605fad3f3575841aab004eea affected < b1f5b890b89cb38a6c0bac91984d56cd69808e8c
7ad6848c7e81a603605fad3f3575841aab004eea affected < a3e0fdf71bbe031de845e8e08ed7fba49f9c702c
Linux Linux affected
Version Status Constraints
2.6.33 affected —
0 unaffected < 2.6.33
4.14.326 unaffected ≤ 4.14.*
4.19.295 unaffected ≤ 4.19.*
5.4.257 unaffected ≤ 5.4.*
5.10.195 unaffected ≤ 5.10.*
5.15.132 unaffected ≤ 5.15.*
6.1.54 unaffected ≤ 6.1.*
6.5.4 unaffected ≤ 6.5.*
6.6 unaffected ≤ *

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/41f10a4d78fe69d685a3172e6884297f233dcf95 cve-icon cve-icon
https://git.kernel.org/stable/c/7586a66b9c4f1b8a825ea1dfa3a91aad5cc7b89b cve-icon cve-icon
https://git.kernel.org/stable/c/895dc4c47171a20035cdaa8d74c1c1e97f2fc974 cve-icon cve-icon
https://git.kernel.org/stable/c/9036b6342fcdab190d6edce3dd447859c1de90fc cve-icon cve-icon
https://git.kernel.org/stable/c/a3e0fdf71bbe031de845e8e08ed7fba49f9c702c cve-icon cve-icon
https://git.kernel.org/stable/c/b1f5b890b89cb38a6c0bac91984d56cd69808e8c cve-icon cve-icon
https://git.kernel.org/stable/c/e918d0211ffbaf039447334c3460cafee1ce0157 cve-icon cve-icon
https://git.kernel.org/stable/c/ed4e0adfa407ab65dd73b8862ebf2f308a0349d2 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025120953-CVE-2023-53831-4dc6@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2023-53831 cve-icon
https://www.cve.org/CVERecord?id=CVE-2023-53831 cve-icon
History

Wed, 10 Dec 2025 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate

Tue, 09 Dec 2025 02:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net: read sk->sk_family once in sk_mc_loop() syzbot is playing with IPV6_ADDRFORM quite a lot these days, and managed to hit the WARN_ON_ONCE(1) in sk_mc_loop() We have many more similar issues to fix. WARNING: CPU: 1 PID: 1593 at net/core/sock.c:782 sk_mc_loop+0x165/0x260 Modules linked in: CPU: 1 PID: 1593 Comm: kworker/1:3 Not tainted 6.1.40-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Workqueue: events_power_efficient gc_worker RIP: 0010:sk_mc_loop+0x165/0x260 net/core/sock.c:782 Code: 34 1b fd 49 81 c7 18 05 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 25 36 6d fd 4d 8b 37 eb 13 e8 db 33 1b fd <0f> 0b b3 01 eb 34 e8 d0 33 1b fd 45 31 f6 49 83 c6 38 4c 89 f0 48 RSP: 0018:ffffc90000388530 EFLAGS: 00010246 RAX: ffffffff846d9b55 RBX: 0000000000000011 RCX: ffff88814f884980 RDX: 0000000000000102 RSI: ffffffff87ae5160 RDI: 0000000000000011 RBP: ffffc90000388550 R08: 0000000000000003 R09: ffffffff846d9a65 R10: 0000000000000002 R11: ffff88814f884980 R12: dffffc0000000000 R13: ffff88810dbee000 R14: 0000000000000010 R15: ffff888150084000 FS: 0000000000000000(0000) GS:ffff8881f6b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000180 CR3: 000000014ee5b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> [<ffffffff8507734f>] ip6_finish_output2+0x33f/0x1ae0 net/ipv6/ip6_output.c:83 [<ffffffff85062766>] __ip6_finish_output net/ipv6/ip6_output.c:200 [inline] [<ffffffff85062766>] ip6_finish_output+0x6c6/0xb10 net/ipv6/ip6_output.c:211 [<ffffffff85061f8c>] NF_HOOK_COND include/linux/netfilter.h:298 [inline] [<ffffffff85061f8c>] ip6_output+0x2bc/0x3d0 net/ipv6/ip6_output.c:232 [<ffffffff852071cf>] dst_output include/net/dst.h:444 [inline] [<ffffffff852071cf>] ip6_local_out+0x10f/0x140 net/ipv6/output_core.c:161 [<ffffffff83618fb4>] ipvlan_process_v6_outbound drivers/net/ipvlan/ipvlan_core.c:483 [inline] [<ffffffff83618fb4>] ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:529 [inline] [<ffffffff83618fb4>] ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline] [<ffffffff83618fb4>] ipvlan_queue_xmit+0x1174/0x1be0 drivers/net/ipvlan/ipvlan_core.c:677 [<ffffffff8361ddd9>] ipvlan_start_xmit+0x49/0x100 drivers/net/ipvlan/ipvlan_main.c:229 [<ffffffff84763fc0>] netdev_start_xmit include/linux/netdevice.h:4925 [inline] [<ffffffff84763fc0>] xmit_one net/core/dev.c:3644 [inline] [<ffffffff84763fc0>] dev_hard_start_xmit+0x320/0x980 net/core/dev.c:3660 [<ffffffff8494c650>] sch_direct_xmit+0x2a0/0x9c0 net/sched/sch_generic.c:342 [<ffffffff8494d883>] qdisc_restart net/sched/sch_generic.c:407 [inline] [<ffffffff8494d883>] __qdisc_run+0xb13/0x1e70 net/sched/sch_generic.c:415 [<ffffffff8478c426>] qdisc_run+0xd6/0x260 include/net/pkt_sched.h:125 [<ffffffff84796eac>] net_tx_action+0x7ac/0x940 net/core/dev.c:5247 [<ffffffff858002bd>] __do_softirq+0x2bd/0x9bd kernel/softirq.c:599 [<ffffffff814c3fe8>] invoke_softirq kernel/softirq.c:430 [inline] [<ffffffff814c3fe8>] __irq_exit_rcu+0xc8/0x170 kernel/softirq.c:683 [<ffffffff814c3f09>] irq_exit_rcu+0x9/0x20 kernel/softirq.c:695
Title net: read sk->sk_family once in sk_mc_loop()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-09T01:29:46.374Z

Reserved: 2025-12-09T01:27:17.825Z

Link: CVE-2023-53831

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-09T16:17:22.017

Modified: 2025-12-09T18:37:13.640

Link: CVE-2023-53831

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-12-09T00:00:00Z

Links: CVE-2023-53831 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.