{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80979", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.811Z", "datePublished": "2026-09-11T19:42:40.171Z", "dateUpdated": "2026-10-19T08:46:03.770Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:46:03.770Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: unregister the connection before draining the rx tasklet\n\nsmc_conn_free() calls smc_ism_unset_conn() only while the link group is\nstill on its device list, and never sets conn->killed.\nsmc_lgr_terminate_sched() unlinks the group immediately and defers killing\nits connections to a work item, so a connection freed in that window keeps\nits smcd->conn[] slot with both gates in smcd_handle_irq() open, and the\ndevice can re-arm the receive tasklet after tasklet_kill() has returned. On\nthe DMB-nocopy path the ghost send buffer is freed right after that drain,\nso the re-armed tasklet dereferences it.\n\nUnregister unconditionally and drain before the detach at both teardown\nsites, mirroring rmb_desc, which smc_buf_unuse() releases after the drain.\nClear conn->sndbuf_desc before freeing it as well, so a reader that samples\nthe pointer cannot get one that is already freed." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The UAF is on the SMC-D DMB-nocopy teardown path, which only loopback-ISM implements; that device accepts a peer only when the GID matches this host, so a local AF_SMC/IPPROTO_SMC pair reaches smc_conn_free()/smcd_handle_irq(), and a remote TCP/CLC peer cannot attach to that fabric.\nAC:L - The attacker owns both sockets and can send on one endpoint to arm smcd_handle_irq() while close() on the other runs smc_conn_free()/smc_conn_kill, which kfree sndbuf_desc before tasklet_kill; they control both sides of the race, so complexity is Low.\nPR:L - socket(AF_SMC) and IPPROTO_SMC listen/connect on ephemeral ports need no capabilities, and loopback-ISM is usable from a user network namespace, so only an unprivileged local account is required.\nUI:N - The attacker performs connect, send, and close on their own SMC sockets; no separate victim action such as mounting a filesystem or opening a file is required.\nS:U - The freed object is a kernel kmalloc smc_buf_desc processed by a tasklet in the same kernel; this is privilege escalation within one security authority, not a VM, IOMMU, or sandbox escape.\nC:H - smcd_cdc_rx_tsklet/smc_cdc_msg_recv_action dereference the freed ghost sndbuf_desc (including ->len); a slab use-after-free of a kmalloc object that the attacker can spray yields an arbitrary kernel read.\nI:H - The same tasklet continues into cursor updates and smc_tx_pending() which write through the recycled descriptor, so heap spraying the use-after-free provides an arbitrary kernel write and control-flow hijack primitive.\nA:H - Tasklet use of the freed smc_buf_desc oopses or panics the kernel even without a full exploit, causing a full system availability loss that the attacker can repeat." } ] } ], "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": "21f6f41e82e59740e26e06e77bdf58dc7f6f08dd", "lessThan": "b6b6ac713ee82b340a8e3be30b101bd2840deec4", "status": "affected", "versionType": "git" }, { "version": "ae2be35cbed2c8385e890147ea321a3fcc3ca5fa", "lessThan": "b4d540ac95cd35c6ebab6afb7eae2bcac7b277a5", "status": "affected", "versionType": "git" }, { "version": "ae2be35cbed2c8385e890147ea321a3fcc3ca5fa", "lessThan": "5bd8b764a610b6b6bc0c4d3d01652747f6e0b5c3", "status": "affected", "versionType": "git" }, { "version": "ae2be35cbed2c8385e890147ea321a3fcc3ca5fa", "lessThan": "b74d313567dfc1b7e56629ddbad04e728686f235", "status": "affected", "versionType": "git" }, { "version": "ae2be35cbed2c8385e890147ea321a3fcc3ca5fa", "lessThan": "36cdf5d48ca191dcd71c28cadbe0981b1d25318d", "status": "affected", "versionType": "git" }, { "version": "6.6.66", "lessThan": "6.6.157", "status": "affected", "versionType": "semver" } ] }, { "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": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "6.6.66", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b6b6ac713ee82b340a8e3be30b101bd2840deec4" }, { "url": "https://git.kernel.org/stable/c/b4d540ac95cd35c6ebab6afb7eae2bcac7b277a5" }, { "url": "https://git.kernel.org/stable/c/5bd8b764a610b6b6bc0c4d3d01652747f6e0b5c3" }, { "url": "https://git.kernel.org/stable/c/b74d313567dfc1b7e56629ddbad04e728686f235" }, { "url": "https://git.kernel.org/stable/c/36cdf5d48ca191dcd71c28cadbe0981b1d25318d" } ], "title": "net/smc: unregister the connection before draining the rx tasklet", "x_generator": { "engine": "bippy-1.2.0" } } } }