{"api_version":"1","generated_at":"2026-04-23T03:05:58+00:00","cve":"CVE-2026-31444","urls":{"html":"https://cve.report/CVE-2026-31444","api":"https://cve.report/api/cve/CVE-2026-31444.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31444","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31444"},"summary":{"title":"ksmbd: fix use-after-free and NULL deref in smb_grant_oplock()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free and NULL deref in smb_grant_oplock()\n\nsmb_grant_oplock() has two issues in the oplock publication sequence:\n\n1) opinfo is linked into ci->m_op_list (via opinfo_add) before\n   add_lease_global_list() is called.  If add_lease_global_list()\n   fails (kmalloc returns NULL), the error path frees the opinfo\n   via __free_opinfo() while it is still linked in ci->m_op_list.\n   Concurrent m_op_list readers (opinfo_get_list, or direct iteration\n   in smb_break_all_levII_oplock) dereference the freed node.\n\n2) opinfo->o_fp is assigned after add_lease_global_list() publishes\n   the opinfo on the global lease list.  A concurrent\n   find_same_lease_key() can walk the lease list and dereference\n   opinfo->o_fp->f_ci while o_fp is still NULL.\n\nFix by restructuring the publication sequence to eliminate post-publish\nfailure:\n\n- Set opinfo->o_fp before any list publication (fixes NULL deref).\n- Preallocate lease_table via alloc_lease_table() before opinfo_add()\n  so add_lease_global_list() becomes infallible after publication.\n- Keep the original m_op_list publication order (opinfo_add before\n  lease list) so concurrent opens via same_client_has_lease() and\n  opinfo_get_list() still see the in-flight grant.\n- Use opinfo_put() instead of __free_opinfo() on err_out so that\n  the RCU-deferred free path is used.\n\nThis also requires splitting add_lease_global_list() to take a\npreallocated lease_table and changing its return type from int to void,\nsince it can no longer fail.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-22 14:16:38","updated_at":"2026-04-22 14:16:38"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/6d7e5a918c1d0aad06db0e17677b66fc9a471021","name":"https://git.kernel.org/stable/c/6d7e5a918c1d0aad06db0e17677b66fc9a471021","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a5c6f6d6ceefed2d5210ee420fb75f8362461f46","name":"https://git.kernel.org/stable/c/a5c6f6d6ceefed2d5210ee420fb75f8362461f46","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9e785f004cbc56390479b77375726ea9b0d1a8a6","name":"https://git.kernel.org/stable/c/9e785f004cbc56390479b77375726ea9b0d1a8a6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7de55bba69cbf0f9280daaea385daf08bc076121","name":"https://git.kernel.org/stable/c/7de55bba69cbf0f9280daaea385daf08bc076121","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/48623ec358c1c600fa1e38368746f933e0f1a617","name":"https://git.kernel.org/stable/c/48623ec358c1c600fa1e38368746f933e0f1a617","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31444","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31444","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 302fef75512b2c8329a3f5efab1ae7ba2562387a 9e785f004cbc56390479b77375726ea9b0d1a8a6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c 7de55bba69cbf0f9280daaea385daf08bc076121 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1d6abf145615dbfe267ce3b0a271f95e3780e18e a5c6f6d6ceefed2d5210ee420fb75f8362461f46 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ce8507ee82c888126d8e7565e27c016308d24cde 6d7e5a918c1d0aad06db0e17677b66fc9a471021 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1dfd062caa165ec9d7ee0823087930f3ab8a6294 48623ec358c1c600fa1e38368746f933e0f1a617 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6.130 6.6.131 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.12.78 6.12.80 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.18.19 6.18.21 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.19.9 6.19.11 semver","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/oplock.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"9e785f004cbc56390479b77375726ea9b0d1a8a6","status":"affected","version":"302fef75512b2c8329a3f5efab1ae7ba2562387a","versionType":"git"},{"lessThan":"7de55bba69cbf0f9280daaea385daf08bc076121","status":"affected","version":"08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c","versionType":"git"},{"lessThan":"a5c6f6d6ceefed2d5210ee420fb75f8362461f46","status":"affected","version":"1d6abf145615dbfe267ce3b0a271f95e3780e18e","versionType":"git"},{"lessThan":"6d7e5a918c1d0aad06db0e17677b66fc9a471021","status":"affected","version":"ce8507ee82c888126d8e7565e27c016308d24cde","versionType":"git"},{"lessThan":"48623ec358c1c600fa1e38368746f933e0f1a617","status":"affected","version":"1dfd062caa165ec9d7ee0823087930f3ab8a6294","versionType":"git"}]},{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/smb/server/oplock.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"6.6.131","status":"affected","version":"6.6.130","versionType":"semver"},{"lessThan":"6.12.80","status":"affected","version":"6.12.78","versionType":"semver"},{"lessThan":"6.18.21","status":"affected","version":"6.18.19","versionType":"semver"},{"lessThan":"6.19.11","status":"affected","version":"6.19.9","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.131","versionStartIncluding":"6.6.130","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.80","versionStartIncluding":"6.12.78","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.21","versionStartIncluding":"6.18.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.11","versionStartIncluding":"6.19.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free and NULL deref in smb_grant_oplock()\n\nsmb_grant_oplock() has two issues in the oplock publication sequence:\n\n1) opinfo is linked into ci->m_op_list (via opinfo_add) before\n   add_lease_global_list() is called.  If add_lease_global_list()\n   fails (kmalloc returns NULL), the error path frees the opinfo\n   via __free_opinfo() while it is still linked in ci->m_op_list.\n   Concurrent m_op_list readers (opinfo_get_list, or direct iteration\n   in smb_break_all_levII_oplock) dereference the freed node.\n\n2) opinfo->o_fp is assigned after add_lease_global_list() publishes\n   the opinfo on the global lease list.  A concurrent\n   find_same_lease_key() can walk the lease list and dereference\n   opinfo->o_fp->f_ci while o_fp is still NULL.\n\nFix by restructuring the publication sequence to eliminate post-publish\nfailure:\n\n- Set opinfo->o_fp before any list publication (fixes NULL deref).\n- Preallocate lease_table via alloc_lease_table() before opinfo_add()\n  so add_lease_global_list() becomes infallible after publication.\n- Keep the original m_op_list publication order (opinfo_add before\n  lease list) so concurrent opens via same_client_has_lease() and\n  opinfo_get_list() still see the in-flight grant.\n- Use opinfo_put() instead of __free_opinfo() on err_out so that\n  the RCU-deferred free path is used.\n\nThis also requires splitting add_lease_global_list() to take a\npreallocated lease_table and changing its return type from int to void,\nsince it can no longer fail."}],"providerMetadata":{"dateUpdated":"2026-04-22T13:53:41.351Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/9e785f004cbc56390479b77375726ea9b0d1a8a6"},{"url":"https://git.kernel.org/stable/c/7de55bba69cbf0f9280daaea385daf08bc076121"},{"url":"https://git.kernel.org/stable/c/a5c6f6d6ceefed2d5210ee420fb75f8362461f46"},{"url":"https://git.kernel.org/stable/c/6d7e5a918c1d0aad06db0e17677b66fc9a471021"},{"url":"https://git.kernel.org/stable/c/48623ec358c1c600fa1e38368746f933e0f1a617"}],"title":"ksmbd: fix use-after-free and NULL deref in smb_grant_oplock()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31444","datePublished":"2026-04-22T13:53:41.351Z","dateReserved":"2026-03-09T15:48:24.090Z","dateUpdated":"2026-04-22T13:53:41.351Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-22 14:16:38","lastModifiedDate":"2026-04-22 14:16:38","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31444","Ordinal":"1","Title":"ksmbd: fix use-after-free and NULL deref in smb_grant_oplock()","CVE":"CVE-2026-31444","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31444","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free and NULL deref in smb_grant_oplock()\n\nsmb_grant_oplock() has two issues in the oplock publication sequence:\n\n1) opinfo is linked into ci->m_op_list (via opinfo_add) before\n   add_lease_global_list() is called.  If add_lease_global_list()\n   fails (kmalloc returns NULL), the error path frees the opinfo\n   via __free_opinfo() while it is still linked in ci->m_op_list.\n   Concurrent m_op_list readers (opinfo_get_list, or direct iteration\n   in smb_break_all_levII_oplock) dereference the freed node.\n\n2) opinfo->o_fp is assigned after add_lease_global_list() publishes\n   the opinfo on the global lease list.  A concurrent\n   find_same_lease_key() can walk the lease list and dereference\n   opinfo->o_fp->f_ci while o_fp is still NULL.\n\nFix by restructuring the publication sequence to eliminate post-publish\nfailure:\n\n- Set opinfo->o_fp before any list publication (fixes NULL deref).\n- Preallocate lease_table via alloc_lease_table() before opinfo_add()\n  so add_lease_global_list() becomes infallible after publication.\n- Keep the original m_op_list publication order (opinfo_add before\n  lease list) so concurrent opens via same_client_has_lease() and\n  opinfo_get_list() still see the in-flight grant.\n- Use opinfo_put() instead of __free_opinfo() on err_out so that\n  the RCU-deferred free path is used.\n\nThis also requires splitting add_lease_global_list() to take a\npreallocated lease_table and changing its return type from int to void,\nsince it can no longer fail.","Type":"Description","Title":"ksmbd: fix use-after-free and NULL deref in smb_grant_oplock()"}]}}}