{ "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": "2026-10-16T19:06:00.447Z" }, "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" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74601", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:01:56.298970Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:06:00.447Z" } } ] } }