CVE-2026-53243rseq: Fix using an uninitialized stack variable in rseq_exit_user_update()
Updated under an hour ago ()
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In the Linux kernel, the following vulnerability has been resolved: rseq: Fix using an uninitialized stack variable in rseq_exit_user_update() There is an bug in which an uninitialized stack variable is used in rseq_exit_user_update() as reported by syzbot: BUG: KMSAN: kernel-infoleak in rseq_set_ids_get_csaddr include/linux/rseq_entry.h:502 [inline] The local variable: struct rseq_ids ids = { .cpu_id = task_cpu(t), .mm_cid = task_mm_cid(t), .node_id = cpu_to_node(ids.cpu_id), }; According to the C standard, the evaluation order of expressions in an initializer list is indeterminately sequenced. The compiler (Clang, in this KMSAN build) evaluates `cpu_to_node(ids.cpu_id)` *before* `ids.cpu_id` is initialized with `task_cpu(t)`. This is fixed by moving the assignment of ids.node_id outside the structure initialization.
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Jun 25, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from d242126fd21ab8f1631fdbc8589e43a9d4229f3b before e12d20a63b61aaf9de4772effccf42cc9a003e58; 82f572449cfe75f12ea985986da60e11f308f77d builds before 6d99479799c69c3cb588fcda19c81d8f61d64ecd | CNA record |
linux linux_kernel linux:linux_kernel | from 7.0.10 before 7.0.13; 7.1; 7.1; 7.1; 7.1 | NVD |
References
- https://git.kernel.org/stable/c/e12d20a63b61aaf9de4772effccf42cc9a003e58patch
- https://git.kernel.org/stable/c/6d99479799c69c3cb588fcda19c81d8f61d64ecdpatch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.