{"id":"CVE-2023-53006","state":"PUBLISHED","title":"cifs: Fix oops due to uncleared server->smbd_conn in reconnect","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: Fix oops due to uncleared server->smbd_conn in reconnect\n\nIn smbd_destroy(), clear the server->smbd_conn pointer after freeing the\nsmbd_connection struct that it points to so that reconnection doesn't get\nconfused.","publishedAt":"2025-03-27T16:43:37.225Z","updatedAt":"2026-10-15T21:41:25.078Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"a9640c0b268405f2540e8203a545e930ea88bb7d","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"91be54849d5392050f5b847b42bd5e6221551ac8","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"e037baee16e0b9ace7e730888fcae9cec11daff2","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"4b83bc6f87eedab4599b0123e572a422689444be","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"5109607a4ece7cd8536172bf7549eb4dce1f3576","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"b7ab9161cf5ddc42a288edf9d1a61f3bdffe17c7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/cifs/smbdirect.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.16","versionType":"semver"},{"version":"4.19.272","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.231","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.166","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.91","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.9","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/cifs/smbdirect.c"]}],"references":["https://git.kernel.org/stable/c/a9640c0b268405f2540e8203a545e930ea88bb7d","https://git.kernel.org/stable/c/91be54849d5392050f5b847b42bd5e6221551ac8","https://git.kernel.org/stable/c/e037baee16e0b9ace7e730888fcae9cec11daff2","https://git.kernel.org/stable/c/4b83bc6f87eedab4599b0123e572a422689444be","https://git.kernel.org/stable/c/5109607a4ece7cd8536172bf7549eb4dce1f3576","https://git.kernel.org/stable/c/b7ab9161cf5ddc42a288edf9d1a61f3bdffe17c7"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/53xxx/CVE-2023-53006.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53006","state":"PUBLISHED","datePublished":"2025-03-27T16:43:37.225Z","dateUpdated":"2026-10-15T21:41:25.078Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-03-27T16:40:15.745Z"},"containers":{"cna":{"title":"cifs: Fix oops due to uncleared server->smbd_conn in reconnect","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: Fix oops due to uncleared server->smbd_conn in reconnect\n\nIn smbd_destroy(), clear the server->smbd_conn pointer after freeing the\nsmbd_connection struct that it points to so that reconnection doesn't get\nconfused."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"a9640c0b268405f2540e8203a545e930ea88bb7d","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"91be54849d5392050f5b847b42bd5e6221551ac8","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"e037baee16e0b9ace7e730888fcae9cec11daff2","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"4b83bc6f87eedab4599b0123e572a422689444be","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"5109607a4ece7cd8536172bf7549eb4dce1f3576","versionType":"git"},{"version":"8ef130f9ec27973f7b49e20c5a3b9134ca33026c","status":"affected","lessThan":"b7ab9161cf5ddc42a288edf9d1a61f3bdffe17c7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/cifs/smbdirect.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.16","versionType":"semver"},{"version":"4.19.272","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.231","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.166","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.91","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.9","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/cifs/smbdirect.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/a9640c0b268405f2540e8203a545e930ea88bb7d"},{"url":"https://git.kernel.org/stable/c/91be54849d5392050f5b847b42bd5e6221551ac8"},{"url":"https://git.kernel.org/stable/c/e037baee16e0b9ace7e730888fcae9cec11daff2"},{"url":"https://git.kernel.org/stable/c/4b83bc6f87eedab4599b0123e572a422689444be"},{"url":"https://git.kernel.org/stable/c/5109607a4ece7cd8536172bf7549eb4dce1f3576"},{"url":"https://git.kernel.org/stable/c/b7ab9161cf5ddc42a288edf9d1a61f3bdffe17c7"}],"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"},"scenarios":[{"lang":"en","value":"AV:N - The UAF is in the CIFS client's SMB Direct reconnect path (`cifs_abort_connection` → `smbd_destroy` → `smbd_reconnect`), driven by a remote peer dropping the RDMA/iWARP connection; iWARP/RoCEv2 are IP-reachable so a malicious or compromised SMB Direct server is a network attacker.\nAC:L - After any disconnect, `__cifs_reconnect` deterministically frees `smbd_conn` then immediately dereferences the dangling pointer in `smbd_reconnect`; the remote peer forces disconnects at will and can retry unboundedly every reconnect cycle.\nPR:N - The attacker is the remote SMB Direct server (or on-path peer) and needs no account or privileges on the victim; the vulnerable abort/reconnect runs in the cifsd kernel thread on the transport before SMB re-authentication.\nUI:N - Against an already-mounted `rdma` CIFS share (typical fstab/autofs enterprise setup), cifsd automatically reconnects on peer disconnect with no victim action at exploit time.\nS:U - The use-after-free corrupts host kernel heap (`smbd_connection` in kmalloc-4k) within the same OS security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - This is a use-after-free of the heap-allocated `smbd_connection`; reclaim/grooming of the freed object lets the reconnect path read attacker-influenced fields (e.g. `transport_status`), yielding a kernel disclosure primitive per UAF guidance.\nI:H - If the reclaimed object presents `transport_status == SMBD_CONNECTED`, `smbd_destroy` runs RDMA teardown (disconnect, QP drain, frees) on attacker-controlled structure fields, giving a classic heap UAF write/control-flow hijack primitive.\nA:H - The dangling `server->smbd_conn` dereference is a confirmed KASAN use-after-free/oops in `smbd_reconnect` during reconnect and is repeatedly triggerable by peer disconnects."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T09:12:20.807Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"4.19.272"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"5.4.231"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"5.10.166"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"5.15.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"6.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"6.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA 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