{"id":"CVE-2026-80986","title":"net/smc: bound the peer rkey counts in SMC-Rv2 LLC messages","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: bound the peer rkey counts in SMC-Rv2 LLC messages\n\nOn a link whose device has max_recv_sge == 1 there is no shared v2 receive\nbuffer, and smc_llc_save_add_lin…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-787"],"vendor":"Linux","product":"Linux","affected":["Linux >= 27ef6a9981fe74191849966a6d5e0400a4008ab8 < 486c699a8cde82c1d9b4f443eeab4ddf86358cb0","Linux >= 27ef6a9981fe74191849966a6d5e0400a4008ab8 < 5e5d9e6df677d30a2203d257b5fd8b99814fa607","Linux >= 27ef6a9981fe74191849966a6d5e0400a4008ab8 < 2d1e7c5aaa3326e95e2058457f172ca99a9a4577","Linux 6.14"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:46:10.570Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80986","references":[{"url":"https://git.kernel.org/stable/c/486c699a8cde82c1d9b4f443eeab4ddf86358cb0"},{"url":"https://git.kernel.org/stable/c/5e5d9e6df677d30a2203d257b5fd8b99814fa607"},{"url":"https://git.kernel.org/stable/c/2d1e7c5aaa3326e95e2058457f172ca99a9a4577"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80986.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-80986"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532205"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80986"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80986"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80986.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00649,"epssPercentile":0.50916,"scores":{"cna":9.8,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.476Z","slug":"CVE-2026-80986","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: bound the peer rkey counts in SMC-Rv2 LLC messages\n\nOn a link whose device has max_recv_sge == 1 there is no shared v2 receive\nbuffer, and smc_llc_save_add_link_rkeys() takes the v2 extension from 44\nbytes past the start of the queue entry's inline message:\n\n  ext = (struct smc_llc_msg_add_link_v2_ext *)(llc_msg + SMC_WR_TX_SIZE);\n\nThe entry is a 72-byte allocation and the extension starts at offset 68, so\next->num_rkeys at offset 94 is already past it. This happens on every\nSMC-Rv2 link addition, whatever the peer sends:\n\n  [    2.490065] BUG: KASAN: slab-out-of-bounds in smc_llc_save_add_link_rkeys+0x333/0x350\n  [    2.490431] Read of size 2 at addr ffff8880056406de by task smctest/106\n  [    2.490709]\n  [    2.490792] CPU: 0 UID: 0 PID: 106 Comm: smctest Not tainted 7.2.0-rc5-p1-g77a5d9d9c99f #32 PREEMPT(lazy)\n  [    2.490795] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n  [    2.490798] Call Trace:\n  [    2.490803]  <TASK>\n  [    2.490805]  dump_stack_lvl+0x53/0x70\n  [    2.490810]  print_report+0xd0/0x630\n  [    2.490828]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n  [    2.490832]  ? smc_llc_save_add_link_rkeys+0x333/0x350\n  [    2.490834]  kasan_report+0xce/0x100\n  [    2.490836]  ? smc_llc_save_add_link_rkeys+0x333/0x350\n  [    2.490837]  smc_llc_save_add_link_rkeys+0x333/0x350\n  [    2.490839]  ? smcr_buf_map_lgr+0x1bf/0x2b0\n  [    2.490844]  smc_llc_cli_add_link+0xca7/0x1e80\n  [    2.490848]  ? smc_llc_wait+0x355/0x810\n  [    2.490850]  ? __pfx_smc_llc_wait+0x10/0x10\n  [    2.490851]  ? __pfx_smc_llc_cli_add_link+0x10/0x10\n  [    2.490853]  ? __pfx_autoremove_wake_function+0x10/0x10\n  [    2.490863]  __smc_connect+0x3f5c/0x4980\n  [    2.490873]  ? __pfx_kernel_connect+0x10/0x10\n  [    2.490888]  ? __pfx___smc_connect+0x10/0x10\n  [    2.490891]  ? release_sock+0x148/0x1d0\n  [    2.490894]  smc_connect+0x42c/0x580\n  [    2.490896]  __sys_connect+0xfc/0x130\n  [    2.490898]  ? __pfx___sys_connect+0x10/0x10\n  [    2.490900]  ? handle_mm_fault+0x1a1/0x430\n  [    2.490908]  __x64_sys_connect+0x6d/0xb0\n  [    2.490909]  ? fpregs_assert_state_consistent+0x56/0xe0\n  [    2.490917]  do_syscall_64+0xf9/0x540\n  [    2.490921]  entry_SYSCALL_64_after_hwframe+0x77/0x7f\n  [    2.490924] RIP: 0033:0x421bb4\n  [    2.490927] Code: ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d ad 34 09 00 00 74 13 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 10 89 55\n  [    2.490929] RSP: 002b:00007ffd473b01a8 EFLAGS: 00000202 ORIG_RAX: 000000000000002a\n  [    2.490935] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000421bb4\n  [    2.490936] RDX: 0000000000000010 RSI: 00007ffd473b01d0 RDI: 0000000000000003\n  [    2.490937] RBP: 0000000000003930 R08: 0000000000000004 R09: 0000000000000000\n  [    2.490938] R10: 00007ffd473b0f98 R11: 0000000000000202 R12: 0000000000000006\n  [    2.490939] R13: 00007ffd473b0f87 R14: 0000000000000003 R15: 00007ffd473b0f90\n  [    2.490940]  </TASK>\n  [    2.490941]\n  [    2.499545] Allocated by task 44:\n  [    2.499693]  kasan_save_stack+0x33/0x60\n  [    2.499860]  kasan_save_track+0x14/0x30\n  [    2.500026]  __kasan_kmalloc+0x8f/0xa0\n  [    2.500190]  __kmalloc_cache_noprof+0x158/0x370\n  [    2.500393]  smc_llc_enqueue+0x72/0x560\n  [    2.500559]  smc_wr_rx_tasklet_fn+0x474/0xa80\n  [    2.500747]  tasklet_action_common+0x20f/0x8a0\n  [    2.500945]  handle_softirqs+0x18e/0x590\n  [    2.501115]  do_softirq+0x3b/0x60\n  [    2.501266]  __local_bh_enable_ip+0x61/0x70\n  [    2.501446]  __alloc_skb+0x732/0x890\n  [    2.501604]  rxe_init_packet+0x16b/0x4f0\n  [    2.501783]  prepare_ack_packet+0xb8/0x830\n  [    2.501962]  rxe_receiver+0x495/0x96e0\n  [    2.502125]  do_work+0x144/0x470\n  [    2.502269]  process_one_work+0x633/0x1030\n  [    2.502450]  worker_thread+0x45b/0xd10\n  [    2.50261\n---truncated---\n\n## Affected\n\n- `Linux >= 27ef6a9981fe74191849966a6d5e0400a4008ab8 < 486c699a8cde82c1d9b4f443eeab4ddf86358cb0`\n- `Linux >= 27ef6a9981fe74191849966a6d5e0400a4008ab8 < 5e5d9e6df677d30a2203d257b5fd8b99814fa607`\n- `Linux >= 27ef6a9981fe74191849966a6d5e0400a4008ab8 < 2d1e7c5aaa3326e95e2058457f172ca99a9a4577`\n- `Linux 6.14`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80986.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":224791,"id":"CVE-2026-80986","ts":1792401544683,"field":"cvss","old":"7","new":"9.8"},{"seq":224790,"id":"CVE-2026-80986","ts":1792401544683,"field":"severity","old":"high","new":"critical"},{"seq":204160,"id":"CVE-2026-80986","ts":1789490234809,"field":"cvss","old":"4.1","new":"7"},{"seq":204159,"id":"CVE-2026-80986","ts":1789490234809,"field":"severity","old":"medium","new":"high"},{"seq":202927,"id":"CVE-2026-80986","ts":1789403732983,"field":"cvss","old":"9.8","new":"4.1"},{"seq":202926,"id":"CVE-2026-80986","ts":1789403732983,"field":"severity","old":"critical","new":"medium"},{"seq":183588,"id":"CVE-2026-80986","ts":1789356676001,"field":"cvss","old":"9.8","new":"4.1"},{"seq":183587,"id":"CVE-2026-80986","ts":1789356676001,"field":"severity","old":"critical","new":"medium"},{"seq":153172,"id":"CVE-2026-80986","ts":1789285349398,"field":"cvss","old":null,"new":"9.8"},{"seq":153171,"id":"CVE-2026-80986","ts":1789285349398,"field":"severity","old":"none","new":"critical"},{"seq":147568,"id":"CVE-2026-80986","ts":1789270211419,"field":"cvss","old":null,"new":"4.1"},{"seq":147567,"id":"CVE-2026-80986","ts":1789270211419,"field":"severity","old":"none","new":"medium"},{"seq":109318,"id":"CVE-2026-80986","ts":1789183731406,"field":"cvss","old":null,"new":"4.1"},{"seq":109317,"id":"CVE-2026-80986","ts":1789183731406,"field":"severity","old":"none","new":"medium"}]}