{"api_version":"1","generated_at":"2026-04-22T21:37:45+00:00","cve":"CVE-2026-31477","urls":{"html":"https://cve.report/CVE-2026-31477","api":"https://cve.report/api/cve/CVE-2026-31477.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31477","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31477"},"summary":{"title":"ksmbd: fix memory leaks and NULL deref in smb2_lock()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix memory leaks and NULL deref in smb2_lock()\n\nsmb2_lock() has three error handling issues after list_del() detaches\nsmb_lock from lock_list at no_check_cl:\n\n1) If vfs_lock_file() returns an unexpected error in the non-UNLOCK\n   path, goto out leaks smb_lock and its flock because the out:\n   handler only iterates lock_list and rollback_list, neither of\n   which contains the detached smb_lock.\n\n2) If vfs_lock_file() returns -ENOENT in the UNLOCK path, goto out\n   leaks smb_lock and flock for the same reason.  The error code\n   returned to the dispatcher is also stale.\n\n3) In the rollback path, smb_flock_init() can return NULL on\n   allocation failure.  The result is dereferenced unconditionally,\n   causing a kernel NULL pointer dereference.  Add a NULL check to\n   prevent the crash and clean up the bookkeeping; the VFS lock\n   itself cannot be rolled back without the allocation and will be\n   released at file or connection teardown.\n\nFix cases 1 and 2 by hoisting the locks_free_lock()/kfree() to before\nthe if(!rc) check in the UNLOCK branch so all exit paths share one\nfree site, and by freeing smb_lock and flock before goto out in the\nnon-UNLOCK branch.  Propagate the correct error code in both cases.\nFix case 3 by wrapping the VFS unlock in an if(rlock) guard and adding\na NULL check for locks_free_lock(rlock) in the shared cleanup.\n\nFound via call-graph analysis using sqry.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-22 14:16:44","updated_at":"2026-04-22 14:16:44"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/c9b95ef6f5039f19e46c3a521a4fe1752d91dfe9","name":"https://git.kernel.org/stable/c/c9b95ef6f5039f19e46c3a521a4fe1752d91dfe9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/cdac6f7e7e428dc70e3b5898ac6999a72ed13993","name":"https://git.kernel.org/stable/c/cdac6f7e7e428dc70e3b5898ac6999a72ed13993","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/91aeaa7256006d79a37298f5a1df23325db91599","name":"https://git.kernel.org/stable/c/91aeaa7256006d79a37298f5a1df23325db91599","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/aab42f0795620cf0d3955a520f571f697d0f9a2a","name":"https://git.kernel.org/stable/c/aab42f0795620cf0d3955a520f571f697d0f9a2a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3cdacd11b41569ce75b3162142240f2355e04900","name":"https://git.kernel.org/stable/c/3cdacd11b41569ce75b3162142240f2355e04900","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/309b44ed684496ed3f9c5715d10b899338623512","name":"https://git.kernel.org/stable/c/309b44ed684496ed3f9c5715d10b899338623512","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31477","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31477","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 cdac6f7e7e428dc70e3b5898ac6999a72ed13993 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 c9b95ef6f5039f19e46c3a521a4fe1752d91dfe9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 91aeaa7256006d79a37298f5a1df23325db91599 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 3cdacd11b41569ce75b3162142240f2355e04900 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 aab42f0795620cf0d3955a520f571f697d0f9a2a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 309b44ed684496ed3f9c5715d10b899338623512 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.168 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.131 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.80 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.21 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.11 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/smb/server/smb2pdu.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"cdac6f7e7e428dc70e3b5898ac6999a72ed13993","status":"affected","version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","versionType":"git"},{"lessThan":"c9b95ef6f5039f19e46c3a521a4fe1752d91dfe9","status":"affected","version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","versionType":"git"},{"lessThan":"91aeaa7256006d79a37298f5a1df23325db91599","status":"affected","version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","versionType":"git"},{"lessThan":"3cdacd11b41569ce75b3162142240f2355e04900","status":"affected","version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","versionType":"git"},{"lessThan":"aab42f0795620cf0d3955a520f571f697d0f9a2a","status":"affected","version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","versionType":"git"},{"lessThan":"309b44ed684496ed3f9c5715d10b899338623512","status":"affected","version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/smb/server/smb2pdu.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.15"},{"lessThan":"5.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.168","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.131","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.80","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.21","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.11","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.168","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.131","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.80","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.21","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.11","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"5.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix memory leaks and NULL deref in smb2_lock()\n\nsmb2_lock() has three error handling issues after list_del() detaches\nsmb_lock from lock_list at no_check_cl:\n\n1) If vfs_lock_file() returns an unexpected error in the non-UNLOCK\n   path, goto out leaks smb_lock and its flock because the out:\n   handler only iterates lock_list and rollback_list, neither of\n   which contains the detached smb_lock.\n\n2) If vfs_lock_file() returns -ENOENT in the UNLOCK path, goto out\n   leaks smb_lock and flock for the same reason.  The error code\n   returned to the dispatcher is also stale.\n\n3) In the rollback path, smb_flock_init() can return NULL on\n   allocation failure.  The result is dereferenced unconditionally,\n   causing a kernel NULL pointer dereference.  Add a NULL check to\n   prevent the crash and clean up the bookkeeping; the VFS lock\n   itself cannot be rolled back without the allocation and will be\n   released at file or connection teardown.\n\nFix cases 1 and 2 by hoisting the locks_free_lock()/kfree() to before\nthe if(!rc) check in the UNLOCK branch so all exit paths share one\nfree site, and by freeing smb_lock and flock before goto out in the\nnon-UNLOCK branch.  Propagate the correct error code in both cases.\nFix case 3 by wrapping the VFS unlock in an if(rlock) guard and adding\na NULL check for locks_free_lock(rlock) in the shared cleanup.\n\nFound via call-graph analysis using sqry."}],"providerMetadata":{"dateUpdated":"2026-04-22T13:54:05.470Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/cdac6f7e7e428dc70e3b5898ac6999a72ed13993"},{"url":"https://git.kernel.org/stable/c/c9b95ef6f5039f19e46c3a521a4fe1752d91dfe9"},{"url":"https://git.kernel.org/stable/c/91aeaa7256006d79a37298f5a1df23325db91599"},{"url":"https://git.kernel.org/stable/c/3cdacd11b41569ce75b3162142240f2355e04900"},{"url":"https://git.kernel.org/stable/c/aab42f0795620cf0d3955a520f571f697d0f9a2a"},{"url":"https://git.kernel.org/stable/c/309b44ed684496ed3f9c5715d10b899338623512"}],"title":"ksmbd: fix memory leaks and NULL deref in smb2_lock()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31477","datePublished":"2026-04-22T13:54:05.470Z","dateReserved":"2026-03-09T15:48:24.098Z","dateUpdated":"2026-04-22T13:54:05.470Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-22 14:16:44","lastModifiedDate":"2026-04-22 14:16:44","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31477","Ordinal":"1","Title":"ksmbd: fix memory leaks and NULL deref in smb2_lock()","CVE":"CVE-2026-31477","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31477","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix memory leaks and NULL deref in smb2_lock()\n\nsmb2_lock() has three error handling issues after list_del() detaches\nsmb_lock from lock_list at no_check_cl:\n\n1) If vfs_lock_file() returns an unexpected error in the non-UNLOCK\n   path, goto out leaks smb_lock and its flock because the out:\n   handler only iterates lock_list and rollback_list, neither of\n   which contains the detached smb_lock.\n\n2) If vfs_lock_file() returns -ENOENT in the UNLOCK path, goto out\n   leaks smb_lock and flock for the same reason.  The error code\n   returned to the dispatcher is also stale.\n\n3) In the rollback path, smb_flock_init() can return NULL on\n   allocation failure.  The result is dereferenced unconditionally,\n   causing a kernel NULL pointer dereference.  Add a NULL check to\n   prevent the crash and clean up the bookkeeping; the VFS lock\n   itself cannot be rolled back without the allocation and will be\n   released at file or connection teardown.\n\nFix cases 1 and 2 by hoisting the locks_free_lock()/kfree() to before\nthe if(!rc) check in the UNLOCK branch so all exit paths share one\nfree site, and by freeing smb_lock and flock before goto out in the\nnon-UNLOCK branch.  Propagate the correct error code in both cases.\nFix case 3 by wrapping the VFS unlock in an if(rlock) guard and adding\na NULL check for locks_free_lock(rlock) in the shared cleanup.\n\nFound via call-graph analysis using sqry.","Type":"Description","Title":"ksmbd: fix memory leaks and NULL deref in smb2_lock()"}]}}}