CVE-2026-74601ring-buffer: Use current_context for safe per-CPU buffer swap
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Use current_context for safe per-CPU buffer swap The ring_buffer_swap_cpu() function currently checks the per-CPU committing counter to determine if a buffer is actively being written to before performing the swap. However, there exists a race window where this check can be bypassed: ring_buffer_lock_reserve cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_a rb_reserve_next_event rb_start_commit // inc committing if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...} __rb_reserve_next rb_move_tail rb_end_commit(cpu_buffer); // dec committing => 0 /* interrupt hits here, successfully swaps! */ local_inc(&cpu_buffer->committing); ring_buffer_unlock_commit cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_b rb_commit rb_end_commit RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)) // triggers warning The committing counter can temporarily drop to 0 during a single write operation (within rb_move_tail), creating a window where swap can succeed even though the write is still in progress. This leads to inconsistent buffer state and triggers the RB_WARN_ON in rb_commit(). Replace the committing counter check with current_context checks, which are set at the entry of ring_buffer_lock_reserve() and remain valid throughout the entire write operation, providing a reliable indicator of buffer busy state during swap.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
- Received
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 4239c38fe0b3847e1e6d962c74b41b08ba0e2990 before 26662bc8fced1d668fa1aa146eda085bfc67bd0b; 4239c38fe0b3847e1e6d962c74b41b08ba0e2990 builds before 6b524e6b234e45c7f5f90d13b042c6f57f80105c; 4239c38fe0b3847e1e6d962c74b41b08ba0e2990 builds before 597f279b7b4a06412e3d965e98cc36e181cdbede; from 4239c38fe0b3847e1e6d962c74b41b08ba0e2990 before 22709117d9ae95e52673685f98caac7c356a8227; from 4239c38fe0b3847e1e6d962c74b41b08ba0e2990 before ad7e10c7ea89af45ac1bf1814855d45da472703d; 4239c38fe0b3847e1e6d962c74b41b08ba0e2990 builds before 5b926fb04cb9ef3156dcf88c69a59d3d1a1c4f9f; 4239c38fe0b3847e1e6d962c74b41b08ba0e2990 builds before 5e6e2a18c20e88167d414f666032792e8bf19b80; from 4239c38fe0b3847e1e6d962c74b41b08ba0e2990 before f27bdc43077e4fcb5557dfc315ee8d91e741f483 | CNA record |
References
- https://git.kernel.org/stable/c/26662bc8fced1d668fa1aa146eda085bfc67bd0b
- https://git.kernel.org/stable/c/6b524e6b234e45c7f5f90d13b042c6f57f80105c
- https://git.kernel.org/stable/c/597f279b7b4a06412e3d965e98cc36e181cdbede
- https://git.kernel.org/stable/c/22709117d9ae95e52673685f98caac7c356a8227
- https://git.kernel.org/stable/c/ad7e10c7ea89af45ac1bf1814855d45da472703d
- https://git.kernel.org/stable/c/5b926fb04cb9ef3156dcf88c69a59d3d1a1c4f9f
- https://git.kernel.org/stable/c/5e6e2a18c20e88167d414f666032792e8bf19b80
- https://git.kernel.org/stable/c/f27bdc43077e4fcb5557dfc315ee8d91e741f483
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.