{"api_version":"1","generated_at":"2026-07-27T22:38:47+00:00","cve":"CVE-2026-64541","urls":{"html":"https://cve.report/CVE-2026-64541","api":"https://cve.report/api/cve/CVE-2026-64541.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64541","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64541"},"summary":{"title":"net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket\n\nsmc_cdc_rx_handler() looks up the connection by token under the link\ngroup's conns_lock, drops the lock, and then dereferences conn and the\nsmc_sock derived from it, ending in sock_hold(&smc->sk) inside\nsmc_cdc_msg_recv(). No reference is held across the lock release.\n\nThe only reference pinning the socket while the connection is\ndiscoverable in the link group is taken in smc_lgr_register_conn()\n(sock_hold) and dropped in __smc_lgr_unregister_conn() (sock_put), both\nunder conns_lock. Once the handler drops conns_lock, a concurrent\nclose() -> smc_release() -> smc_conn_free() -> smc_lgr_unregister_conn()\ncan drop that reference and free the smc_sock, so the handler's later\nsock_hold() runs on freed memory:\n\n  WARNING: lib/refcount.c:25 at refcount_warn_saturate\n  Workqueue: rxe_wq do_work\n   refcount_warn_saturate (lib/refcount.c:25)\n   smc_cdc_msg_recv (net/smc/smc_cdc.c:430)\n   smc_cdc_rx_handler (net/smc/smc_cdc.c:502)\n   smc_wr_rx_tasklet_fn (net/smc/smc_wr.c:445)\n   tasklet_action_common (kernel/softirq.c:938)\n   handle_softirqs (kernel/softirq.c:622)\n  Kernel panic - not syncing: panic_on_warn set\n\nOnly SMC-R is affected. The SMC-D receive tasklet is stopped by\ntasklet_kill(&conn->rx_tsklet) in smc_conn_free() before the connection\nis unregistered, so it cannot run concurrently with the free.\n\nTake the socket reference while still holding conns_lock, so the\nregistration reference can no longer be the last one, and drop it once\nthe handler is done.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-27 21:17:06","updated_at":"2026-07-27 21:17:06"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/472e9d7c0d5b03be3ff91ff941f57da822b031bc","name":"https://git.kernel.org/stable/c/472e9d7c0d5b03be3ff91ff941f57da822b031bc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9d160b35cc34a2ba8229d07651468a7848325135","name":"https://git.kernel.org/stable/c/9d160b35cc34a2ba8229d07651468a7848325135","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/647b19e5cc145a2f1f685ae8ff3805a17356888c","name":"https://git.kernel.org/stable/c/647b19e5cc145a2f1f685ae8ff3805a17356888c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb","name":"https://git.kernel.org/stable/c/3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1951bffbc6493ec34cff3956b29d4bc6606904a6","name":"https://git.kernel.org/stable/c/1951bffbc6493ec34cff3956b29d4bc6606904a6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8145b432136285e01091815b48ceb2dae261f262","name":"https://git.kernel.org/stable/c/8145b432136285e01091815b48ceb2dae261f262","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ce5aa8084329351086894aa34d77e40301d5bd3d","name":"https://git.kernel.org/stable/c/ce5aa8084329351086894aa34d77e40301d5bd3d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8de4f665d0febfb92803dece377791a563fc7041","name":"https://git.kernel.org/stable/c/8de4f665d0febfb92803dece377791a563fc7041","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64541","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64541","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d7b0e37c1ac152905b18a5b9506179091a35b0b6 8de4f665d0febfb92803dece377791a563fc7041 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d7b0e37c1ac152905b18a5b9506179091a35b0b6 8145b432136285e01091815b48ceb2dae261f262 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d7b0e37c1ac152905b18a5b9506179091a35b0b6 1951bffbc6493ec34cff3956b29d4bc6606904a6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d7b0e37c1ac152905b18a5b9506179091a35b0b6 647b19e5cc145a2f1f685ae8ff3805a17356888c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d7b0e37c1ac152905b18a5b9506179091a35b0b6 472e9d7c0d5b03be3ff91ff941f57da822b031bc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d7b0e37c1ac152905b18a5b9506179091a35b0b6 3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d7b0e37c1ac152905b18a5b9506179091a35b0b6 ce5aa8084329351086894aa34d77e40301d5bd3d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d7b0e37c1ac152905b18a5b9506179091a35b0b6 9d160b35cc34a2ba8229d07651468a7848325135 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.18","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.18 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.261 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.212 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc3 * original_commit_for_fix","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":["net/smc/smc_cdc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"8de4f665d0febfb92803dece377791a563fc7041","status":"affected","version":"d7b0e37c1ac152905b18a5b9506179091a35b0b6","versionType":"git"},{"lessThan":"8145b432136285e01091815b48ceb2dae261f262","status":"affected","version":"d7b0e37c1ac152905b18a5b9506179091a35b0b6","versionType":"git"},{"lessThan":"1951bffbc6493ec34cff3956b29d4bc6606904a6","status":"affected","version":"d7b0e37c1ac152905b18a5b9506179091a35b0b6","versionType":"git"},{"lessThan":"647b19e5cc145a2f1f685ae8ff3805a17356888c","status":"affected","version":"d7b0e37c1ac152905b18a5b9506179091a35b0b6","versionType":"git"},{"lessThan":"472e9d7c0d5b03be3ff91ff941f57da822b031bc","status":"affected","version":"d7b0e37c1ac152905b18a5b9506179091a35b0b6","versionType":"git"},{"lessThan":"3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb","status":"affected","version":"d7b0e37c1ac152905b18a5b9506179091a35b0b6","versionType":"git"},{"lessThan":"ce5aa8084329351086894aa34d77e40301d5bd3d","status":"affected","version":"d7b0e37c1ac152905b18a5b9506179091a35b0b6","versionType":"git"},{"lessThan":"9d160b35cc34a2ba8229d07651468a7848325135","status":"affected","version":"d7b0e37c1ac152905b18a5b9506179091a35b0b6","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/smc/smc_cdc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.18"},{"lessThan":"4.18","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.261","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.212","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.261","versionStartIncluding":"4.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.212","versionStartIncluding":"4.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"4.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"4.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"4.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"4.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"4.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc3","versionStartIncluding":"4.18","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket\n\nsmc_cdc_rx_handler() looks up the connection by token under the link\ngroup's conns_lock, drops the lock, and then dereferences conn and the\nsmc_sock derived from it, ending in sock_hold(&smc->sk) inside\nsmc_cdc_msg_recv(). No reference is held across the lock release.\n\nThe only reference pinning the socket while the connection is\ndiscoverable in the link group is taken in smc_lgr_register_conn()\n(sock_hold) and dropped in __smc_lgr_unregister_conn() (sock_put), both\nunder conns_lock. Once the handler drops conns_lock, a concurrent\nclose() -> smc_release() -> smc_conn_free() -> smc_lgr_unregister_conn()\ncan drop that reference and free the smc_sock, so the handler's later\nsock_hold() runs on freed memory:\n\n  WARNING: lib/refcount.c:25 at refcount_warn_saturate\n  Workqueue: rxe_wq do_work\n   refcount_warn_saturate (lib/refcount.c:25)\n   smc_cdc_msg_recv (net/smc/smc_cdc.c:430)\n   smc_cdc_rx_handler (net/smc/smc_cdc.c:502)\n   smc_wr_rx_tasklet_fn (net/smc/smc_wr.c:445)\n   tasklet_action_common (kernel/softirq.c:938)\n   handle_softirqs (kernel/softirq.c:622)\n  Kernel panic - not syncing: panic_on_warn set\n\nOnly SMC-R is affected. The SMC-D receive tasklet is stopped by\ntasklet_kill(&conn->rx_tsklet) in smc_conn_free() before the connection\nis unregistered, so it cannot run concurrently with the free.\n\nTake the socket reference while still holding conns_lock, so the\nregistration reference can no longer be the last one, and drop it once\nthe handler is done."}],"providerMetadata":{"dateUpdated":"2026-07-27T20:10:34.439Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/8de4f665d0febfb92803dece377791a563fc7041"},{"url":"https://git.kernel.org/stable/c/8145b432136285e01091815b48ceb2dae261f262"},{"url":"https://git.kernel.org/stable/c/1951bffbc6493ec34cff3956b29d4bc6606904a6"},{"url":"https://git.kernel.org/stable/c/647b19e5cc145a2f1f685ae8ff3805a17356888c"},{"url":"https://git.kernel.org/stable/c/472e9d7c0d5b03be3ff91ff941f57da822b031bc"},{"url":"https://git.kernel.org/stable/c/3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb"},{"url":"https://git.kernel.org/stable/c/ce5aa8084329351086894aa34d77e40301d5bd3d"},{"url":"https://git.kernel.org/stable/c/9d160b35cc34a2ba8229d07651468a7848325135"}],"title":"net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64541","datePublished":"2026-07-27T20:10:34.439Z","dateReserved":"2026-07-19T15:36:31.795Z","dateUpdated":"2026-07-27T20:10:34.439Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-27 21:17:06","lastModifiedDate":"2026-07-27 21:17:06","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64541","Ordinal":"1","Title":"net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket","CVE":"CVE-2026-64541","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64541","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket\n\nsmc_cdc_rx_handler() looks up the connection by token under the link\ngroup's conns_lock, drops the lock, and then dereferences conn and the\nsmc_sock derived from it, ending in sock_hold(&smc->sk) inside\nsmc_cdc_msg_recv(). No reference is held across the lock release.\n\nThe only reference pinning the socket while the connection is\ndiscoverable in the link group is taken in smc_lgr_register_conn()\n(sock_hold) and dropped in __smc_lgr_unregister_conn() (sock_put), both\nunder conns_lock. Once the handler drops conns_lock, a concurrent\nclose() -> smc_release() -> smc_conn_free() -> smc_lgr_unregister_conn()\ncan drop that reference and free the smc_sock, so the handler's later\nsock_hold() runs on freed memory:\n\n  WARNING: lib/refcount.c:25 at refcount_warn_saturate\n  Workqueue: rxe_wq do_work\n   refcount_warn_saturate (lib/refcount.c:25)\n   smc_cdc_msg_recv (net/smc/smc_cdc.c:430)\n   smc_cdc_rx_handler (net/smc/smc_cdc.c:502)\n   smc_wr_rx_tasklet_fn (net/smc/smc_wr.c:445)\n   tasklet_action_common (kernel/softirq.c:938)\n   handle_softirqs (kernel/softirq.c:622)\n  Kernel panic - not syncing: panic_on_warn set\n\nOnly SMC-R is affected. The SMC-D receive tasklet is stopped by\ntasklet_kill(&conn->rx_tsklet) in smc_conn_free() before the connection\nis unregistered, so it cannot run concurrently with the free.\n\nTake the socket reference while still holding conns_lock, so the\nregistration reference can no longer be the last one, and drop it once\nthe handler is done.","Type":"Description","Title":"net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket"}]}}}