{"id":"CVE-2025-68240","state":"PUBLISHED","title":"nilfs2: avoid having an active sc_timer before freeing sci","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: avoid having an active sc_timer before freeing sci\n\nBecause kthread_stop did not stop sc_task properly and returned -EINTR,\nthe sc_timer was not properly closed, ultimately causing the problem [1]\nreported by syzbot when freeing sci due to the sc_timer not being closed.\n\nBecause the thread sc_task main function nilfs_segctor_thread() returns 0\nwhen it succeeds, when the return value of kthread_stop() is not 0 in\nnilfs_segctor_destroy(), we believe that it has not properly closed\nsc_timer.\n\nWe use timer_shutdown_sync() to sync wait for sc_timer to shutdown, and\nset the value of sc_task to NULL under the protection of lock\nsc_state_lock, so as to avoid the issue caused by sc_timer not being\nproperly shutdowned.\n\n[1]\nODEBUG: free active (active state 0) object: 00000000dacb411a object type: timer_list hint: nilfs_construction_timeout\nCall trace:\n nilfs_segctor_destroy fs/nilfs2/segment.c:2811 [inline]\n nilfs_detach_log_writer+0x668/0x8cc fs/nilfs2/segment.c:2877\n nilfs_put_super+0x4c/0x12c fs/nilfs2/super.c:509","publishedAt":"2025-12-16T14:21:17.710Z","updatedAt":"2026-05-11T21:49:32.618Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3f66cc261ccb54a8e4d8d5aa51c389c19453b00c","status":"affected","lessThan":"36049e81dc7f077e0e24d5b9688a7458beacef8f","versionType":"git"},{"version":"3f66cc261ccb54a8e4d8d5aa51c389c19453b00c","status":"affected","lessThan":"2f65799e2a736d556d306440c4e1e8906736117a","versionType":"git"},{"version":"3f66cc261ccb54a8e4d8d5aa51c389c19453b00c","status":"affected","lessThan":"9a6b60cb147d53968753a34805211d2e5e08c027","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nilfs2/segment.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.12","versionType":"semver"},{"version":"6.12.59","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.9","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nilfs2/segment.c"]}],"references":["https://git.kernel.org/stable/c/36049e81dc7f077e0e24d5b9688a7458beacef8f","https://git.kernel.org/stable/c/2f65799e2a736d556d306440c4e1e8906736117a","https://git.kernel.org/stable/c/9a6b60cb147d53968753a34805211d2e5e08c027"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:56.034Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/68xxx/CVE-2025-68240.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-68240","state":"PUBLISHED","datePublished":"2025-12-16T14:21:17.710Z","dateUpdated":"2026-05-11T21:49:32.618Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-12-16T13:41:40.263Z"},"containers":{"cna":{"title":"nilfs2: avoid having an active sc_timer before freeing sci","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: avoid having an active sc_timer before freeing sci\n\nBecause kthread_stop did not stop sc_task properly and returned -EINTR,\nthe sc_timer was not properly closed, ultimately causing the problem [1]\nreported by syzbot when freeing sci due to the sc_timer not being closed.\n\nBecause the thread sc_task main function nilfs_segctor_thread() returns 0\nwhen it succeeds, when the return value of kthread_stop() is not 0 in\nnilfs_segctor_destroy(), we believe that it has not properly closed\nsc_timer.\n\nWe use timer_shutdown_sync() to sync wait for sc_timer to shutdown, and\nset the value of sc_task to NULL under the protection of lock\nsc_state_lock, so as to avoid the issue caused by sc_timer not being\nproperly shutdowned.\n\n[1]\nODEBUG: free active (active state 0) object: 00000000dacb411a object type: timer_list hint: nilfs_construction_timeout\nCall trace:\n nilfs_segctor_destroy fs/nilfs2/segment.c:2811 [inline]\n nilfs_detach_log_writer+0x668/0x8cc fs/nilfs2/segment.c:2877\n nilfs_put_super+0x4c/0x12c fs/nilfs2/super.c:509"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3f66cc261ccb54a8e4d8d5aa51c389c19453b00c","status":"affected","lessThan":"36049e81dc7f077e0e24d5b9688a7458beacef8f","versionType":"git"},{"version":"3f66cc261ccb54a8e4d8d5aa51c389c19453b00c","status":"affected","lessThan":"2f65799e2a736d556d306440c4e1e8906736117a","versionType":"git"},{"version":"3f66cc261ccb54a8e4d8d5aa51c389c19453b00c","status":"affected","lessThan":"9a6b60cb147d53968753a34805211d2e5e08c027","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nilfs2/segment.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.12","versionType":"semver"},{"version":"6.12.59","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.9","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nilfs2/segment.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/36049e81dc7f077e0e24d5b9688a7458beacef8f"},{"url":"https://git.kernel.org/stable/c/2f65799e2a736d556d306440c4e1e8906736117a"},{"url":"https://git.kernel.org/stable/c/9a6b60cb147d53968753a34805211d2e5e08c027"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:49:32.618Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.12.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.17.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.18"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}