{"id":"CVE-2026-90247","state":"PUBLISHED","title":"bpf: Fix mmap_lock leak in irq_work path","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix mmap_lock leak in irq_work path\n\nstack_map_get_build_id_offset() introduced a per-CPU irq_work to defer\nmmap_read_unlock() from NMI context, and bpf_find_vma() later reused the\nsame mmap_unlock_work. Both callers only check whether the work is busy\nbefore taking mmap_lock, so a nested caller can reuse the slot before the\nfirst caller queues it. Two read locks may then be acquired while only one\ndeferred unlock runs, leaking a read lock and blocking exit_mmap().\n\nReserve the per-CPU slot before mmap_read_trylock(). Use the same wrapper\nin stackmap and bpf_find_vma() so both callers release the reservation on\ntrylock failure. Keep rejecting the slot while the irq_work remains busy.\nRelease it after the irq_work callback unlocks the mm.","publishedAt":"2026-09-17T16:07:49.444Z","updatedAt":"2026-10-30T12:34:55.059Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"d6d091873e12d1de36d7228c4f452e6cace3a23e","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"b6c9daf6097f9b39162b8e736a6ac7caf5ef6fc8","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"931f62311c058d79f29548f20943969bb441ce87","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"a052ad5edccf5319f50ed955de4368f8318a9f20","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"051f2da26ce377f683b938a3382e0f16d02f3139","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"fa9dcacdcdf487f0ffef64bf67622f1caed509f1","versionType":"git"},{"version":"a7f4da875c16f3b8bef0d9ec67528111045bfcd8","status":"affected","versionType":"git"},{"version":"f1838da73cccb238b8be4ef464fce0168dc7ba84","status":"affected","versionType":"git"},{"version":"4.19.92","status":"affected","lessThan":"4.20","versionType":"semver"},{"version":"5.4.7","status":"affected","lessThan":"5.5","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/mmap_unlock_work.h","kernel/bpf/stackmap.c","kernel/bpf/task_iter.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/mmap_unlock_work.h","kernel/bpf/stackmap.c","kernel/bpf/task_iter.c"]}],"references":["https://git.kernel.org/stable/c/d6d091873e12d1de36d7228c4f452e6cace3a23e","https://git.kernel.org/stable/c/b6c9daf6097f9b39162b8e736a6ac7caf5ef6fc8","https://git.kernel.org/stable/c/931f62311c058d79f29548f20943969bb441ce87","https://git.kernel.org/stable/c/a052ad5edccf5319f50ed955de4368f8318a9f20","https://git.kernel.org/stable/c/051f2da26ce377f683b938a3382e0f16d02f3139","https://git.kernel.org/stable/c/fa9dcacdcdf487f0ffef64bf67622f1caed509f1"],"weaknesses":[],"ingestedAt":"2026-10-30T12:54:04.478Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90247.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90247","state":"PUBLISHED","datePublished":"2026-09-17T16:07:49.444Z","dateUpdated":"2026-10-30T12:34:55.059Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.795Z"},"containers":{"cna":{"title":"bpf: Fix mmap_lock leak in irq_work path","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix mmap_lock leak in irq_work path\n\nstack_map_get_build_id_offset() introduced a per-CPU irq_work to defer\nmmap_read_unlock() from NMI context, and bpf_find_vma() later reused the\nsame mmap_unlock_work. Both callers only check whether the work is busy\nbefore taking mmap_lock, so a nested caller can reuse the slot before the\nfirst caller queues it. Two read locks may then be acquired while only one\ndeferred unlock runs, leaking a read lock and blocking exit_mmap().\n\nReserve the per-CPU slot before mmap_read_trylock(). Use the same wrapper\nin stackmap and bpf_find_vma() so both callers release the reservation on\ntrylock failure. Keep rejecting the slot while the irq_work remains busy.\nRelease it after the irq_work callback unlocks the mm."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"d6d091873e12d1de36d7228c4f452e6cace3a23e","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"b6c9daf6097f9b39162b8e736a6ac7caf5ef6fc8","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"931f62311c058d79f29548f20943969bb441ce87","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"a052ad5edccf5319f50ed955de4368f8318a9f20","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"051f2da26ce377f683b938a3382e0f16d02f3139","versionType":"git"},{"version":"eac9153f2b584c702cea02c1f1a57d85aa9aea42","status":"affected","lessThan":"fa9dcacdcdf487f0ffef64bf67622f1caed509f1","versionType":"git"},{"version":"a7f4da875c16f3b8bef0d9ec67528111045bfcd8","status":"affected","versionType":"git"},{"version":"f1838da73cccb238b8be4ef464fce0168dc7ba84","status":"affected","versionType":"git"},{"version":"4.19.92","status":"affected","lessThan":"4.20","versionType":"semver"},{"version":"5.4.7","status":"affected","lessThan":"5.5","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/mmap_unlock_work.h","kernel/bpf/stackmap.c","kernel/bpf/task_iter.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/mmap_unlock_work.h","kernel/bpf/stackmap.c","kernel/bpf/task_iter.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/d6d091873e12d1de36d7228c4f452e6cace3a23e"},{"url":"https://git.kernel.org/stable/c/b6c9daf6097f9b39162b8e736a6ac7caf5ef6fc8"},{"url":"https://git.kernel.org/stable/c/931f62311c058d79f29548f20943969bb441ce87"},{"url":"https://git.kernel.org/stable/c/a052ad5edccf5319f50ed955de4368f8318a9f20"},{"url":"https://git.kernel.org/stable/c/051f2da26ce377f683b938a3382e0f16d02f3139"},{"url":"https://git.kernel.org/stable/c/fa9dcacdcdf487f0ffef64bf67622f1caed509f1"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:34:55.059Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.7"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}