CVE-2022-49450
CVE-2022-49450 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.
Key facts
- Severity: Medium (CVSS 3.x base score 5.5)
- EPSS exploit prediction: 0% (20th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2022-54779
- Weakness: CWE-476
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix listen() setting the bar too high for the prealloc rings AF_RXRPC's listen() handler lets you set the backlog up to 32 (if you bump up the sysctl), but whilst the preallocation circular buffers have 32 slots in them, one of them has to be a dead slot because we're using CIRC_CNT(). This means that listen(rxrpc_sock, 32) will cause an oops when the socket is closed because rxrpc_service_prealloc_one() allocated one too many calls and rxrpc_discard_prealloc() won't then be able to get rid of them because it'll think the ring is empty. rxrpc_release_calls_on_socket() then tries to abort them, but oopses because call->peer isn't yet set. Fix this by setting the maximum backlog to RXRPC_BACKLOG_MAX - 1 to match the ring capacity. BUG: kernel NULL pointer dereference, address: 0000000000000086 ... RIP: 0010:rxrpc_send_abort_packet+0x73/0x240 [rxrpc] Call Trace: <TASK> ? __wake_up_common_lock+0x7a/0x90 ? rxrpc_notify_socket+0x8e/0x140 [rxrpc] ? rxrpc_abort_call+0x4c/0x60 [rxrpc] rxrpc_release_calls_on_socket+0x107/0x1a0 [rxrpc] rxrpc_release+0xc9/0x1c0 [rxrpc] __sock_release+0x37/0xa0 sock_close+0x11/0x20 __fput+0x89/0x240 task_work_run+0x59/0x90 do_exit+0x319/0xaa0
Frequently asked questions
- What is CVE-2022-49450?
- In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix listen() setting the bar too high for the prealloc rings AF_RXRPC's listen() handler lets you set the backlog up to 32 (if you bump up the sysctl), but whilst the preallocation circular buffers have 32 slots in them, one of them has to be a dead slot because we're using CIRC_CNT(). This means that listen(rxrpc_sock, 32) will cause an oops when the socket is closed because rxrpc_service_prealloc_one() allocated one too many calls and rxrpc_discard_prealloc() won't then be able to get rid of them because it'll think the ring is empty. rxrpc_release_calls_on_socket() then tries to abort them, but oopses because call->peer isn't yet set. Fix this by setting the maximum backlog to RXRPC_BACKLOG_MAX - 1 to match the ring capacity. BUG: kernel NULL pointer dereference, address: 0000000000000086 ... RIP: 0010:rxrpc_send_abort_packet+0x73/0x240 [rxrpc] Call Trace: <TASK> ? __wake_up_common_lock+0x7a/0x90 ? rxrpc_notify_socket+0x8e/0x140 [rxrpc] ? rxrpc_abort_call+0x4c/0x60 [rxrpc] rxrpc_release_calls_on_socket+0x107/0x1a0 [rxrpc] rxrpc_release+0xc9/0x1c0 [rxrpc] __sock_release+0x37/0xa0 sock_close+0x11/0x20 __fput+0x89/0x240 task_work_run+0x59/0x90 do_exit+0x319/0xaa0
- How severe is CVE-2022-49450?
- CVE-2022-49450 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2022-49450 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2022-49450?
- CVE-2022-49450 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2022-49450?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2022-49450 have an EU (EUVD) identifier?
- Yes. CVE-2022-49450 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2022-54779.
- When was CVE-2022-49450 published?
- CVE-2022-49450 was published on 2025-02-26 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/369de57492c4f1a42563c5a3bd365822ca3bfc79
- https://git.kernel.org/stable/c/4a3a78b7918bdd723d8c7c9786522ca969bffcc4
- https://git.kernel.org/stable/c/5b4826657d36c218e9f08e8d3223b0edce3de88f
- https://git.kernel.org/stable/c/616f76498d5ddf26b997caf64a95cda3c8a55533
- https://git.kernel.org/stable/c/61fb38cfbb1d54d3dafd0c25752f684b3cd00b32
- https://git.kernel.org/stable/c/88e22159750b0d55793302eeed8ee603f5c1a95c
- https://git.kernel.org/stable/c/91b34bf0409f43bb60453bab23c5beadd726d022
- https://git.kernel.org/stable/c/b3a9b227d5e7467b8518160ff034ea22bb9de573
- https://git.kernel.org/stable/c/e198f1930050e3115c80b67d9249f80f98a27c67
Affected products (1)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
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