{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31444","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-03-09T15:48:24.090Z","datePublished":"2026-04-22T13:53:41.351Z","dateUpdated":"2026-04-27T14:03:10.086Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-04-27T14:03:10.086Z"},"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."}],"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/oplock.c"],"versions":[{"version":"302fef75512b2c8329a3f5efab1ae7ba2562387a","lessThan":"9e785f004cbc56390479b77375726ea9b0d1a8a6","status":"affected","versionType":"git"},{"version":"08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c","lessThan":"7de55bba69cbf0f9280daaea385daf08bc076121","status":"affected","versionType":"git"},{"version":"1d6abf145615dbfe267ce3b0a271f95e3780e18e","lessThan":"a5c6f6d6ceefed2d5210ee420fb75f8362461f46","status":"affected","versionType":"git"},{"version":"ce8507ee82c888126d8e7565e27c016308d24cde","lessThan":"6d7e5a918c1d0aad06db0e17677b66fc9a471021","status":"affected","versionType":"git"},{"version":"1dfd062caa165ec9d7ee0823087930f3ab8a6294","lessThan":"48623ec358c1c600fa1e38368746f933e0f1a617","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/oplock.c"],"versions":[{"version":"6.6.130","lessThan":"6.6.131","status":"affected","versionType":"semver"},{"version":"6.12.78","lessThan":"6.12.80","status":"affected","versionType":"semver"},{"version":"6.18.19","lessThan":"6.18.21","status":"affected","versionType":"semver"},{"version":"6.19.9","lessThan":"6.19.11","status":"affected","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.130","versionEndExcluding":"6.6.131"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.78","versionEndExcluding":"6.12.80"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18.19","versionEndExcluding":"6.18.21"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19.9","versionEndExcluding":"6.19.11"}]}]}],"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"}}}}