{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74601","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.919Z","datePublished":"2026-08-22T15:31:50.092Z","dateUpdated":"2026-08-25T05:40:26.170Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-25T05:40:26.170Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Use current_context for safe per-CPU buffer swap\n\nThe ring_buffer_swap_cpu() function currently checks the per-CPU\ncommitting counter to determine if a buffer is actively being written to\nbefore performing the swap. However, there exists a race window where\nthis check can be bypassed:\n\n    ring_buffer_lock_reserve\n        cpu_buffer = buffer->buffers[cpu];       // cpu_buffer_a\n        rb_reserve_next_event\n            rb_start_commit // inc committing\n            if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...}\n            __rb_reserve_next\n                rb_move_tail\n                    rb_end_commit(cpu_buffer);   // dec committing => 0\n                    /* interrupt hits here, successfully swaps! */\n                    local_inc(&cpu_buffer->committing);\n\n    ring_buffer_unlock_commit\n        cpu_buffer = buffer->buffers[cpu];      // cpu_buffer_b\n        rb_commit\n            rb_end_commit\n            RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing))\n                                                // triggers warning\n\nThe committing counter can temporarily drop to 0 during a single write\noperation (within rb_move_tail), creating a window where swap can\nsucceed even though the write is still in progress. This leads to\ninconsistent buffer state and triggers the RB_WARN_ON in rb_commit().\n\nReplace the committing counter check with current_context checks, which\nare set at the entry of ring_buffer_lock_reserve() and remain valid\nthroughout the entire write operation, providing a reliable indicator of\nbuffer busy state during swap."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires local tracefs writes to snapshot or latency tracers; ring_buffer_swap_cpu() is only reached from update_max_tr_single() via tracing_snapshot_write or irqsoff/preemptoff tracers, with no network, adjacent, or physical entry path.\nAC:L - The attacker controls both sides of the race by enabling irqsoff/preemptoff tracing or hammering per_cpu/*/snapshot while generating trace events that cross page boundaries, reliably hitting the rb_move_tail window where committing briefly drops to zero.\nPR:L - tracing_check_open_get_tr() enforces only LOCKDOWN_TRACEFS and DAC with no capable() check; tracefs gid= mounts, Android/Perfetto/ChromeOS tracing groups, and container user+mount namespaces routinely grant unprivileged local write access to snapshot and current_tracer.\nUI:N - The attacker enables tracers and triggers buffer swaps through their own tracefs writes and syscalls; no victim cooperation, unrelated user action, or third-party interaction is required.\nS:U - Impact is corrupted kernel ring-buffer metadata and WARN_ON within the same kernel security domain; this is not a VM escape, IOMMU bypass, or cross-authority sandbox breakout.\nC:H - Swapping per-CPU buffers mid-write leaves ring_buffer_per_cpu page, tail, and commit state inconsistent across buffers; subsequent trace reads or commits can access wrong backing pages, constituting kernel-memory corruption with arbitrary-read potential.\nI:H - Mid-reservation buffer swap causes unlock_commit on the wrong cpu_buffer with mismatched tail/commit page pointers, corrupting ring-buffer page lists and write metadata in ways exploitable for heap corruption and control-flow manipulation.\nA:H - rb_end_commit() hits RB_WARN_ON triggering WARN_ON and disabling recording; corrupted ring-buffer page state from this swap race has caused kernel oops/panic in related ring_buffer_swap_cpu bugs, and panic_on_warn makes the WARN fatal."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/ring_buffer.c"],"versions":[{"version":"4239c38fe0b3847e1e6d962c74b41b08ba0e2990","lessThan":"26662bc8fced1d668fa1aa146eda085bfc67bd0b","status":"affected","versionType":"git"},{"version":"4239c38fe0b3847e1e6d962c74b41b08ba0e2990","lessThan":"6b524e6b234e45c7f5f90d13b042c6f57f80105c","status":"affected","versionType":"git"},{"version":"4239c38fe0b3847e1e6d962c74b41b08ba0e2990","lessThan":"597f279b7b4a06412e3d965e98cc36e181cdbede","status":"affected","versionType":"git"},{"version":"4239c38fe0b3847e1e6d962c74b41b08ba0e2990","lessThan":"22709117d9ae95e52673685f98caac7c356a8227","status":"affected","versionType":"git"},{"version":"4239c38fe0b3847e1e6d962c74b41b08ba0e2990","lessThan":"ad7e10c7ea89af45ac1bf1814855d45da472703d","status":"affected","versionType":"git"},{"version":"4239c38fe0b3847e1e6d962c74b41b08ba0e2990","lessThan":"5b926fb04cb9ef3156dcf88c69a59d3d1a1c4f9f","status":"affected","versionType":"git"},{"version":"4239c38fe0b3847e1e6d962c74b41b08ba0e2990","lessThan":"5e6e2a18c20e88167d414f666032792e8bf19b80","status":"affected","versionType":"git"},{"version":"4239c38fe0b3847e1e6d962c74b41b08ba0e2990","lessThan":"f27bdc43077e4fcb5557dfc315ee8d91e741f483","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/ring_buffer.c"],"versions":[{"version":"4.5","status":"affected"},{"version":"0","lessThan":"4.5","status":"unaffected","versionType":"semver"},{"version":"5.10.266","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.217","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.184","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.153","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.105","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.45","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.9","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"5.10.266"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"5.15.217"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"6.1.184"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"6.6.153"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"6.12.105"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/26662bc8fced1d668fa1aa146eda085bfc67bd0b"},{"url":"https://git.kernel.org/stable/c/6b524e6b234e45c7f5f90d13b042c6f57f80105c"},{"url":"https://git.kernel.org/stable/c/597f279b7b4a06412e3d965e98cc36e181cdbede"},{"url":"https://git.kernel.org/stable/c/22709117d9ae95e52673685f98caac7c356a8227"},{"url":"https://git.kernel.org/stable/c/ad7e10c7ea89af45ac1bf1814855d45da472703d"},{"url":"https://git.kernel.org/stable/c/5b926fb04cb9ef3156dcf88c69a59d3d1a1c4f9f"},{"url":"https://git.kernel.org/stable/c/5e6e2a18c20e88167d414f666032792e8bf19b80"},{"url":"https://git.kernel.org/stable/c/f27bdc43077e4fcb5557dfc315ee8d91e741f483"}],"title":"ring-buffer: Use current_context for safe per-CPU buffer swap","x_generator":{"engine":"bippy-1.2.0"}}}}