{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64401", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.785Z", "datePublished": "2026-07-25T08:50:44.361Z", "dateUpdated": "2026-07-25T08:50:44.361Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-25T08:50:44.361Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: resolve SWN tcon from live registrations\n\ncifs_swn_notify() looks up a witness registration by id under\ncifs_swnreg_idr_mutex, drops the mutex, and then uses the registration's\ncached tcon pointer. That pointer is not a lifetime reference, and it is\nnot a stable representative once cifs_get_swn_reg() lets multiple tcons\nfor the same net/share name share one registration id.\n\nA same-share second mount can keep the cifs_swn_reg alive after the first\ntcon unregisters and is freed. The registration then still points at the\nfreed first tcon, so taking tc_lock or incrementing tc_count through\nswnreg->tcon only moves the use-after-free earlier. Taking tc_lock while\nholding cifs_swnreg_idr_mutex also violates the documented CIFS lock\norder.\n\nFix this by making the registration store only the stable witness\nidentity: id, net name, share name, and notify flags. When a notify\narrives, copy that identity under cifs_swnreg_idr_mutex, drop the mutex,\nthen find and pin a live witness tcon that currently matches the net/share\npair under the normal cifs_tcp_ses_lock -> tc_lock order. The notification\npath uses that pinned tcon directly and drops the reference when done.\n\nRegistration and unregister messages now use the live tcon passed by the\ncaller instead of a cached tcon in the registration. The final unregister\nsend is folded into cifs_swn_unregister() while the registration is still\nprotected by cifs_swnreg_idr_mutex. This removes the previous\nfind/drop/reacquire raw-pointer window. The release path only removes the\nidr entry and frees the stable identity strings.\n\nThis preserves the intended one-registration/many-tcon behavior: a\nregistration id represents a net/share pair, and notify handling acts on a\nlive representative selected at use time. It also preserves CLIENT_MOVE\nordering for the representative tcon because the old-IP unregister is sent\nbefore cifs_swn_register() sends the new-IP register."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/cifs_swn.c", "fs/smb/client/trace.h"], "versions": [{"version": "fed979a7e082bd9f25f9002c3c4f8740dacd0bc8", "lessThan": "51d18db392e5386a7bb9e816d611f14e600cca3c", "status": "affected", "versionType": "git"}, {"version": "fed979a7e082bd9f25f9002c3c4f8740dacd0bc8", "lessThan": "aa3c0cab4b28c5007ec570c63e1d6ad6943ed0fd", "status": "affected", "versionType": "git"}, {"version": "fed979a7e082bd9f25f9002c3c4f8740dacd0bc8", "lessThan": "945b4a4a54497db1dcb2f20ef801a84e884dac21", "status": "affected", "versionType": "git"}, {"version": "fed979a7e082bd9f25f9002c3c4f8740dacd0bc8", "lessThan": "91b8a58c6ac15c7db6518f696389933282f88da7", "status": "affected", "versionType": "git"}, {"version": "fed979a7e082bd9f25f9002c3c4f8740dacd0bc8", "lessThan": "0700f946659d0ab2352ec8a9b1c6fc74b13a27d7", "status": "affected", "versionType": "git"}, {"version": "fed979a7e082bd9f25f9002c3c4f8740dacd0bc8", "lessThan": "ec457f9afe5ae9538bdcd58fd4cb442b9787e183", "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/client/cifs_swn.c", "fs/smb/client/trace.h"], "versions": [{"version": "5.11", "status": "affected"}, {"version": "0", "lessThan": "5.11", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2-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": "5.11", "versionEndExcluding": "6.1.178"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.12.97"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.18.39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.2-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/51d18db392e5386a7bb9e816d611f14e600cca3c"}, {"url": "https://git.kernel.org/stable/c/aa3c0cab4b28c5007ec570c63e1d6ad6943ed0fd"}, {"url": "https://git.kernel.org/stable/c/945b4a4a54497db1dcb2f20ef801a84e884dac21"}, {"url": "https://git.kernel.org/stable/c/91b8a58c6ac15c7db6518f696389933282f88da7"}, {"url": "https://git.kernel.org/stable/c/0700f946659d0ab2352ec8a9b1c6fc74b13a27d7"}, {"url": "https://git.kernel.org/stable/c/ec457f9afe5ae9538bdcd58fd4cb442b9787e183"}], "title": "smb: client: resolve SWN tcon from live registrations", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fed979a7e082bd9f25f9002c3c4f8740dacd0bc8,51d18db392e5386a7bb9e816d611f14e600cca3c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fed979a7e082bd9f25f9002c3c4f8740dacd0bc8,aa3c0cab4b28c5007ec570c63e1d6ad6943ed0fd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fed979a7e082bd9f25f9002c3c4f8740dacd0bc8,945b4a4a54497db1dcb2f20ef801a84e884dac21)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fed979a7e082bd9f25f9002c3c4f8740dacd0bc8,91b8a58c6ac15c7db6518f696389933282f88da7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fed979a7e082bd9f25f9002c3c4f8740dacd0bc8,0700f946659d0ab2352ec8a9b1c6fc74b13a27d7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fed979a7e082bd9f25f9002c3c4f8740dacd0bc8,ec457f9afe5ae9538bdcd58fd4cb442b9787e183)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "5.11"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,5.11)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.178,6.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.145,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.97,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.39,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.4,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2-rc1,*)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-25T16:45:05.589292+00:00", "updated": "2026-07-25T16:45:05.589356+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}