CVE-2026-74493

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74493", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.906Z", "datePublished": "2026-08-15T12:27:21.980Z", "dateUpdated": "2026-10-16T19:05:50.062Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:37:50.842Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix socket use-after-free during link group termination\n\n__smc_lgr_terminate() drops conns_lock after finding a connection in\nlgr->conns_all, but before taking a reference on its socket. The connection\nis embedded in the socket, and its registration reference protects it only\nwhile the connection remains in the tree.\n\nA concurrent close can unregister the connection and drop that reference,\nfreeing the socket before the termination worker reaches sock_hold().\n\nThe race is reachable when close overlaps link group termination.\nLocal stress testing reproduced the use-after-free and KASAN reported:\n\n BUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc]\n Write of size 4 by task kworker/3:3\n Workqueue: events smc_lgr_terminate_work [smc]\n __smc_lgr_terminate.part.0 [smc]\n\nThe socket was allocated by smc_create(), freed through\nslab_free_after_rcu_debug(), and was followed by:\n\n refcount_t: addition on 0; use-after-free.\n __smc_lgr_terminate.part.0 [smc]\n\nTake the socket reference while conns_lock still protects the tree entry.\nThe unregister path then cannot drop the last reference until termination\nhas finished using the socket."}], "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 bug is hit in __smc_lgr_terminate() when a link group shuts down; that path is driven by SMC LLC control messages from a remote peer over RoCE/RDMA (smc_llc_rx_handler), including DELETE_LINK_ALL and protocol-violation termination, not only local syscalls.\nAC:L - An SMC peer can overlap link-group termination with connection teardown by sending DELETE_LINK_ALL (or a terminating LLC event) while aborting/closing the same session; the fix report shows reliable stress reproduction, and the attacker controls both sides of the terminate/close race.\nPR:N - Exploitation needs only completing an SMC handshake as a network peer to the victim; no local account, capabilities, or namespace admin rights on the victim host are required beyond normal remote connectivity to the SMC service.\nUI:N - No victim user action is needed; a remote peer can trigger termination and concurrent connection teardown purely through kernel protocol handling, without the user mounting filesystems, opening files, or performing other interactive steps.\nS:U - The impact stays within the host kernel boundary (memory corruption and potential local privilege escalation) and does not cross VM, container, or IOMMU security authorities into another trust domain.\nC:H - KASAN reported slab-use-after-free in __smc_lgr_terminate with refcount_t addition on 0 during sock_hold() on a freed smc_sock; UAF on kernel heap objects can be turned into arbitrary kernel memory disclosure via heap grooming.\nI:H - The UAF is a write of size 4 to freed socket memory during sock_hold(), giving a kernel heap corruption primitive that can be developed into arbitrary write or control-flow hijack for kernel code execution.\nA:H - The reported UAF occurs in the smc_lgr_terminate workqueue and can crash the kernel (oops/panic); repeated remote triggering against SMC/RoCE services can also cause sustained denial of service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/smc/smc_core.c"], "versions": [{"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "ff44f2df57fb5560bdc75eb977867643e764a262", "status": "affected", "versionType": "git"}, {"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "9fb17c95b8f0683570fca1fb2792264147af937a", "status": "affected", "versionType": "git"}, {"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "bea8dc14de2d56aca749d368563e6888217710a5", "status": "affected", "versionType": "git"}, {"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "5a42f162b857019a4c10ff687dc3bcdf51831865", "status": "affected", "versionType": "git"}, {"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "281c103a8eaed59001ce952f231df1b07674215a", "status": "affected", "versionType": "git"}, {"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "f807a63d0d95680c34f677700da9148a07d7c78f", "status": "affected", "versionType": "git"}, {"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "f0541a775d04c88e90ba448e35ce0d743512822a", "status": "affected", "versionType": "git"}, {"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "f621d6ebeebb6374342571e4ddf45fdbc420f6cd", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/smc/smc_core.c"], "versions": [{"version": "5.5", "status": "affected"}, {"version": "0", "lessThan": "5.5", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "5.5", "versionEndExcluding": "5.10.265"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.15.216"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.1.183"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.6.151"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.12.103"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.18.44"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "7.1.8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/ff44f2df57fb5560bdc75eb977867643e764a262"}, {"url": "https://git.kernel.org/stable/c/9fb17c95b8f0683570fca1fb2792264147af937a"}, {"url": "https://git.kernel.org/stable/c/bea8dc14de2d56aca749d368563e6888217710a5"}, {"url": "https://git.kernel.org/stable/c/5a42f162b857019a4c10ff687dc3bcdf51831865"}, {"url": "https://git.kernel.org/stable/c/281c103a8eaed59001ce952f231df1b07674215a"}, {"url": "https://git.kernel.org/stable/c/f807a63d0d95680c34f677700da9148a07d7c78f"}, {"url": "https://git.kernel.org/stable/c/f0541a775d04c88e90ba448e35ce0d743512822a"}, {"url": "https://git.kernel.org/stable/c/f621d6ebeebb6374342571e4ddf45fdbc420f6cd"}], "title": "net/smc: fix socket use-after-free during link group termination", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74493", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T18:58:11.763137Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:05:50.062Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74493", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T18:58:11.763137Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T18:58:12.687Z"}}], "cna": {"title": "net/smc: fix socket use-after-free during link group termination", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 9.8, "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - The bug is hit in __smc_lgr_terminate() when a link group shuts down; that path is driven by SMC LLC control messages from a remote peer over RoCE/RDMA (smc_llc_rx_handler), including DELETE_LINK_ALL and protocol-violation termination, not only local syscalls.\nAC:L - An SMC peer can overlap link-group termination with connection teardown by sending DELETE_LINK_ALL (or a terminating LLC event) while aborting/closing the same session; the fix report shows reliable stress reproduction, and the attacker controls both sides of the terminate/close race.\nPR:N - Exploitation needs only completing an SMC handshake as a network peer to the victim; no local account, capabilities, or namespace admin rights on the victim host are required beyond normal remote connectivity to the SMC service.\nUI:N - No victim user action is needed; a remote peer can trigger termination and concurrent connection teardown purely through kernel protocol handling, without the user mounting filesystems, opening files, or performing other interactive steps.\nS:U - The impact stays within the host kernel boundary (memory corruption and potential local privilege escalation) and does not cross VM, container, or IOMMU security authorities into another trust domain.\nC:H - KASAN reported slab-use-after-free in __smc_lgr_terminate with refcount_t addition on 0 during sock_hold() on a freed smc_sock; UAF on kernel heap objects can be turned into arbitrary kernel memory disclosure via heap grooming.\nI:H - The UAF is a write of size 4 to freed socket memory during sock_hold(), giving a kernel heap corruption primitive that can be developed into arbitrary write or control-flow hijack for kernel code execution.\nA:H - The reported UAF occurs in the smc_lgr_terminate workqueue and can crash the kernel (oops/panic); repeated remote triggering against SMC/RoCE services can also cause sustained denial of service."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "ff44f2df57fb5560bdc75eb977867643e764a262", "versionType": "git"}, {"status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "9fb17c95b8f0683570fca1fb2792264147af937a", "versionType": "git"}, {"status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "bea8dc14de2d56aca749d368563e6888217710a5", "versionType": "git"}, {"status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "5a42f162b857019a4c10ff687dc3bcdf51831865", "versionType": "git"}, {"status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "281c103a8eaed59001ce952f231df1b07674215a", "versionType": "git"}, {"status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "f807a63d0d95680c34f677700da9148a07d7c78f", "versionType": "git"}, {"status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "f0541a775d04c88e90ba448e35ce0d743512822a", "versionType": "git"}, {"status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "lessThan": "f621d6ebeebb6374342571e4ddf45fdbc420f6cd", "versionType": "git"}], "programFiles": ["net/smc/smc_core.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.5"}, {"status": "unaffected", "version": "0", "lessThan": "5.5", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.265", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.216", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.183", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.151", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.103", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.44", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.8", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/smc/smc_core.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/ff44f2df57fb5560bdc75eb977867643e764a262"}, {"url": "https://git.kernel.org/stable/c/9fb17c95b8f0683570fca1fb2792264147af937a"}, {"url": "https://git.kernel.org/stable/c/bea8dc14de2d56aca749d368563e6888217710a5"}, {"url": "https://git.kernel.org/stable/c/5a42f162b857019a4c10ff687dc3bcdf51831865"}, {"url": "https://git.kernel.org/stable/c/281c103a8eaed59001ce952f231df1b07674215a"}, {"url": "https://git.kernel.org/stable/c/f807a63d0d95680c34f677700da9148a07d7c78f"}, {"url": "https://git.kernel.org/stable/c/f0541a775d04c88e90ba448e35ce0d743512822a"}, {"url": "https://git.kernel.org/stable/c/f621d6ebeebb6374342571e4ddf45fdbc420f6cd"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix socket use-after-free during link group termination\n\n__smc_lgr_terminate() drops conns_lock after finding a connection in\nlgr->conns_all, but before taking a reference on its socket. The connection\nis embedded in the socket, and its registration reference protects it only\nwhile the connection remains in the tree.\n\nA concurrent close can unregister the connection and drop that reference,\nfreeing the socket before the termination worker reaches sock_hold().\n\nThe race is reachable when close overlaps link group termination.\nLocal stress testing reproduced the use-after-free and KASAN reported:\n\n BUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc]\n Write of size 4 by task kworker/3:3\n Workqueue: events smc_lgr_terminate_work [smc]\n __smc_lgr_terminate.part.0 [smc]\n\nThe socket was allocated by smc_create(), freed through\nslab_free_after_rcu_debug(), and was followed by:\n\n refcount_t: addition on 0; use-after-free.\n __smc_lgr_terminate.part.0 [smc]\n\nTake the socket reference while conns_lock still protects the tree entry.\nThe unregister path then cannot drop the last reference until termination\nhas finished using the socket."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.265", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.216", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.183", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.151", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.103", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.44", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.8", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "5.5"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:37:50.842Z"}}}, "cveMetadata": {"cveId": "CVE-2026-74493", "state": "PUBLISHED", "dateUpdated": "2026-10-16T19:05:50.062Z", "dateReserved": "2026-08-15T05:44:03.906Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-15T12:27:21.980Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/smc/smc_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "ff44f2df57fb5560bdc75eb977867643e764a262", "status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "versionType": "git"}, {"lessThan": "9fb17c95b8f0683570fca1fb2792264147af937a", "status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "versionType": "git"}, {"lessThan": "bea8dc14de2d56aca749d368563e6888217710a5", "status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "versionType": "git"}, {"lessThan": "5a42f162b857019a4c10ff687dc3bcdf51831865", "status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "versionType": "git"}, {"lessThan": "281c103a8eaed59001ce952f231df1b07674215a", "status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "versionType": "git"}, {"lessThan": "f807a63d0d95680c34f677700da9148a07d7c78f", "status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "versionType": "git"}, {"lessThan": "f0541a775d04c88e90ba448e35ce0d743512822a", "status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "versionType": "git"}, {"lessThan": "f621d6ebeebb6374342571e4ddf45fdbc420f6cd", "status": "affected", "version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/smc/smc_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.5"}, {"lessThan": "5.5", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.265", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.216", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.183", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.151", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.103", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.44", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.8", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix socket use-after-free during link group termination\n\n__smc_lgr_terminate() drops conns_lock after finding a connection in\nlgr->conns_all, but before taking a reference on its socket. The connection\nis embedded in the socket, and its registration reference protects it only\nwhile the connection remains in the tree.\n\nA concurrent close can unregister the connection and drop that reference,\nfreeing the socket before the termination worker reaches sock_hold().\n\nThe race is reachable when close overlaps link group termination.\nLocal stress testing reproduced the use-after-free and KASAN reported:\n\n BUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc]\n Write of size 4 by task kworker/3:3\n Workqueue: events smc_lgr_terminate_work [smc]\n __smc_lgr_terminate.part.0 [smc]\n\nThe socket was allocated by smc_create(), freed through\nslab_free_after_rcu_debug(), and was followed by:\n\n refcount_t: addition on 0; use-after-free.\n __smc_lgr_terminate.part.0 [smc]\n\nTake the socket reference while conns_lock still protects the tree entry.\nThe unregister path then cannot drop the last reference until termination\nhas finished using the socket."}], "id": "CVE-2026-74493", "lastModified": "2026-10-16T20:17:32.280", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-74493", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T18:58:11.763137Z", "version": "2.0.3"}}]}, "published": "2026-08-15T13:17:54.240", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/281c103a8eaed59001ce952f231df1b07674215a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5a42f162b857019a4c10ff687dc3bcdf51831865"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9fb17c95b8f0683570fca1fb2792264147af937a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bea8dc14de2d56aca749d368563e6888217710a5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f0541a775d04c88e90ba448e35ce0d743512822a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f621d6ebeebb6374342571e4ddf45fdbc420f6cd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f807a63d0d95680c34f677700da9148a07d7c78f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ff44f2df57fb5560bdc75eb977867643e764a262"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net/smc: fix socket use-after-free during link group termination", "id": "2517059", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2517059"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet/smc: fix socket use-after-free during link group termination\n__smc_lgr_terminate() drops conns_lock after finding a connection in\nlgr->conns_all, but before taking a reference on its socket. The connection\nis embedded in the socket, and its registration reference protects it only\nwhile the connection remains in the tree.\nA concurrent close can unregister the connection and drop that reference,\nfreeing the socket before the termination worker reaches sock_hold().\nThe race is reachable when close overlaps link group termination.\nLocal stress testing reproduced the use-after-free and KASAN reported:\nBUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc]\nWrite of size 4 by task kworker/3:3\nWorkqueue: events smc_lgr_terminate_work [smc]\n__smc_lgr_terminate.part.0 [smc]\nThe socket was allocated by smc_create(), freed through\nslab_free_after_rcu_debug(), and was followed by:\nrefcount_t: addition on 0; use-after-free.\n__smc_lgr_terminate.part.0 [smc]\nTake the socket reference while conns_lock still protects the tree entry.\nThe unregister path then cannot drop the last reference until termination\nhas finished using the socket.", "A flaw was found in the Linux kernel's net/smc component. A use-after-free vulnerability occurs during link group termination when a concurrent close operation unregisters a connection and frees its socket before the termination worker can properly hold the socket. This race condition can lead to a system crash, resulting in a denial of service."], "name": "CVE-2026-74493", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74493\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74493\nhttps://lore.kernel.org/linux-cve-announce/2026081539-CVE-2026-74493-cf51@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[69318b5215f2dc32c345a3d65b98b4b1bf29c007,5a42f162b857019a4c10ff687dc3bcdf51831865)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[69318b5215f2dc32c345a3d65b98b4b1bf29c007,281c103a8eaed59001ce952f231df1b07674215a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[69318b5215f2dc32c345a3d65b98b4b1bf29c007,f807a63d0d95680c34f677700da9148a07d7c78f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[69318b5215f2dc32c345a3d65b98b4b1bf29c007,f0541a775d04c88e90ba448e35ce0d743512822a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[69318b5215f2dc32c345a3d65b98b4b1bf29c007,f621d6ebeebb6374342571e4ddf45fdbc420f6cd)"}}], "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": "generic", "value": "5.5"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.5)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.151,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.103,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.44,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.8,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc6,*]"}}], "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": "2026-08-15T16:00:07.794316+00:00", "updated": "2026-08-21T21:30:17.756566+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}