{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31718","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-03-09T15:48:24.134Z","datePublished":"2026-05-01T13:56:12.680Z","dateUpdated":"2026-05-11T22:14:24.915Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T22:14:24.915Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger\n\nWhen a durable file handle survives session disconnect (TCP close without\nSMB2_LOGOFF), session_fd_check() sets fp->conn = NULL to preserve the\nhandle for later reconnection. However, it did not clean up the byte-range\nlocks on fp->lock_list.\n\nLater, when the durable scavenger thread times out and calls\n__ksmbd_close_fd(NULL, fp), the lock cleanup loop did:\n\n    spin_lock(&fp->conn->llist_lock);\n\nThis caused a slab use-after-free because fp->conn was NULL and the\noriginal connection object had already been freed by\nksmbd_tcp_disconnect().\n\nThe root cause is asymmetric cleanup: lock entries (smb_lock->clist) were\nleft dangling on the freed conn->lock_list while fp->conn was nulled out.\n\nTo fix this issue properly, we need to handle the lifetime of\nsmb_lock->clist across three paths:\n - Safely skip clist deletion when list is empty and fp->conn is NULL.\n - Remove the lock from the old connection's lock_list in\n   session_fd_check()\n - Re-add the lock to the new connection's lock_list in\n   ksmbd_reopen_durable_fd()."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"}}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/vfs_cache.c"],"versions":[{"version":"c8efcc786146a951091588e5fa7e3c754850cb3c","lessThan":"e33c65f011980b4ad4abfd93585ec2079856368f","status":"affected","versionType":"git"},{"version":"c8efcc786146a951091588e5fa7e3c754850cb3c","lessThan":"3d6682726c2d3a46d31dae88b8166786b09b03ad","status":"affected","versionType":"git"},{"version":"c8efcc786146a951091588e5fa7e3c754850cb3c","lessThan":"b34fc42cfe922e551f7a27d3ac3bb016e41d7dd9","status":"affected","versionType":"git"},{"version":"c8efcc786146a951091588e5fa7e3c754850cb3c","lessThan":"235e32320a470fcd3998fb3774f2290a0eb302a1","status":"affected","versionType":"git"},{"version":"8df4bcdb0a4232192b2445256c39b787d58ef14d","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/vfs_cache.c"],"versions":[{"version":"6.9","status":"affected"},{"version":"0","lessThan":"6.9","status":"unaffected","versionType":"semver"},{"version":"6.12.84","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.25","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.2","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1-rc1","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":"6.9","versionEndExcluding":"6.12.84"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.18.25"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"7.0.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"7.1-rc1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.32"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/e33c65f011980b4ad4abfd93585ec2079856368f"},{"url":"https://git.kernel.org/stable/c/3d6682726c2d3a46d31dae88b8166786b09b03ad"},{"url":"https://git.kernel.org/stable/c/b34fc42cfe922e551f7a27d3ac3bb016e41d7dd9"},{"url":"https://git.kernel.org/stable/c/235e32320a470fcd3998fb3774f2290a0eb302a1"}],"title":"ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger","x_generator":{"engine":"bippy-1.2.0"}}}}