CVE-2026-43215

/* * Conceptual PoC demonstrating the locking issue. * This code simulates the incorrect locking usage that leads to race conditions. */ // Incorrect usage (Vulnerable path) // spin_lock(&cifs_tcp_ses_lock); // access_tcon_field(tcon); // spin_unlock(&cifs_tcp_ses_lock); // Correct usage (Patched path) // spin_lock(&tcon->tc_lock); // access_tcon_field(tcon); // spin_unlock(&tcon->tc_lock); // Triggering the race requires concurrent CIFS operations. // Example: Multi-threaded mount/unmount or file IO on a malicious SMB share.

{"cve": {"id": "CVE-2026-43215", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:41.063", "lastModified": "2026-05-11T19:44:10.940", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: Fix locking usage for tcon fields\n\nWe used to use the cifs_tcp_ses_lock to protect a lot of objects\nthat are not just the server, ses or tcon lists. We later introduced\nsrv_lock, ses_lock and tc_lock to protect fields within the\ncorresponding structs. This was done to provide a more granular\nprotection and avoid unnecessary serialization.\n\nThere were still a couple of uses of cifs_tcp_ses_lock to provide\ntcon fields. In this patch, I've replaced them with tc_lock."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-667"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.6.128", "matchCriteriaId": "6FE38AB6-B81E-42D1-8F9E-C6AE1F58C425"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3969db6b22e3d90d8c5f22ac1a7fe0350a94c136", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/601dd3b79769b38d30b693c40afdb2a4b7edf9d0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/8c59eeeeffa1524ef57e173a89a1a3ff539888d5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/953953abb66e52c224057ab91e404284fefeab62", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/96c4af418586ee9a6aab61738644366426e05316", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}