CVE-2022-49420: net: annotate races around sk->sk_bound_dev_if
In the Linux kernel, the following vulnerability has been resolved:
net: annotate races around sk->sk_bound_dev_if
UDP sendmsg() is lockless, and reads sk->sk_bound_dev_if while
this field can be changed by another thread.
Adds minimal annotations to avoid KCSAN splats for UDP.
Following patches will add more annotations to potential lockless readers.
BUG: KCSAN: data-race in __ip6_datagram_connect / udpv6_sendmsg
write to 0xffff888136d47a94 of 4 bytes by task 7681 on cpu 0:
__ip6_datagram_connect+0x6e2/0x930 net/ipv6/datagram.c:221
ip6_datagram_connect+0x2a/0x40 net/ipv6/datagram.c:272
inet_dgram_connect+0x107/0x190 net/ipv4/af_inet.c:576
__sys_connect_file net/socket.c:1900 [inline]
__sys_connect+0x197/0x1b0 net/socket.c:1917
__do_sys_connect net/socket.c:1927 [inline]
__se_sys_connect net/socket.c:1924 [inline]
__x64_sys_connect+0x3d/0x50 net/socket.c:1924
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff888136d47a94 of 4 bytes by task 7670 on cpu 1:
udpv6_sendmsg+0xc60/0x16e0 net/ipv6/udp.c:1436
inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:652
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg net/socket.c:725 [inline]
____sys_sendmsg+0x39a/0x510 net/socket.c:2413
___sys_sendmsg net/socket.c:2467 [inline]
__sys_sendmmsg+0x267/0x4c0 net/socket.c:2553
__do_sys_sendmmsg net/socket.c:2582 [inline]
__se_sys_sendmmsg net/socket.c:2579 [inline]
__x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0x00000000 -> 0xffffff9b
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7670 Comm: syz-executor.3 Tainted: G W 5.18.0-rc1-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
I chose to not add Fixes: tag because race has minor consequences
and stable teams busy enough.
Security readout for executives and security teams
Plain-English summary
CVE-2022-49420 is a Linux kernel networking issue involving a race condition in UDP/IPv6 socket handling. The public record describes it as having “minor consequences” and provides no CVSS score. There is no KEV listing or source evidence of active exploitation.
Executive priority
Low immediate urgency based on current public evidence. Track through normal Linux kernel patch management unless your vendor rates it higher or confirms a security impact for your environment.
Technical view
The issue is a data race around sk->sk_bound_dev_if. UDP sendmsg() can read this field without locking while another thread changes it during IPv6 datagram connect handling. The upstream change adds race annotations to address KCSAN reports, not a clearly described memory-corruption or privilege-escalation flaw.
Likely exposure
Exposure appears limited to systems running affected Linux kernel versions identified in the CVE data, including 5.18.3 and 5.19. Distribution kernels may differ due to backports. Confirm against vendor advisories and kernel build metadata.
Exploitation context
The source bundle does not describe practical exploitation, attacker requirements, or security impact beyond a KCSAN-detected race. The CVE is not marked as CISA KEV. Treat active exploitation as unconfirmed.
Researcher notes
This CVE is unusual because the commit message frames the change as KCSAN annotation for a minor race, with no Fixes tag. Public data lacks CVSS, CWE, exploitation detail, and concrete impact. Assess using vendor kernel advisories rather than assuming exploitability.
Mitigation direction
Check your Linux distribution’s advisory for CVE-2022-49420 coverage.
Update to a vendor-supported kernel containing the referenced stable fixes.
If self-maintaining kernels, review the referenced stable commits for backport status.
Prioritize internet-facing or multi-tenant Linux workloads after vendor impact confirmation.
Validation and detection
Inventory Linux kernel versions across servers, containers hosts, and appliances.
Compare kernel builds with vendor advisories for CVE-2022-49420.
Check whether referenced stable commits are present or backported.
Document exceptions where vendor status is unavailable or not affected.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
cve · low confidence lookup
CVE-2022-49420 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
0CVSS vectors
3Timeline events
0ADP providers
3Source links
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
CVE publishedCVE Program
The CVE record was published.
Feb 26, 2025, 02:12 UTC (UTC+00:00)
CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.