{"id":"CVE-2026-80981","revision":"ae66f3883aa340f7a63f20bef6100168","records":[{"revision":"ae66f3883aa340f7a63f20bef6100168","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80981","aliases":[],"title":"net/smc: fix use-after-free of the LLC qentry in smc_llc_srv_add_link()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix use-after-free of the LLC qentry in smc_llc_srv_add_link()\n\nsmc_llc_srv_add_link() keeps add_llc pointing into the queue entry:\n\n add_llc = &qentry->msg.add_link;\t\t\tsmc_llc.c:1482\n ...\n smc_llc_save_add_link_info(link_new, add_llc);\tsmc_llc.c:1494\n smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);\t\tsmc_llc.c:1495\n ...\n u8 *llc_msg = smc_link_shared_v2_rxbuf(link) ?\n\t(u8 *)lgr->wr_rx_buf_v2 : (u8 *)add_llc;\tsmc_llc.c:1504\n smc_llc_save_add_link_rkeys(link, link_new, llc_msg);\tsmc_llc.c:1506\n\nsmc_llc_flow_qentry_del() kfree()s the entry, so on a link without a shared\nv2 receive buffer the pointer handed to smc_llc_save_add_link_rkeys() is\nalready freed. Before the Fixes: commit that branch always used\nlgr->wr_rx_buf_v2 and add_llc was not used after the free.\n\nReproduced on an unpatched tree over rxe, with KASAN, kasan_multi_shot\nand a link forced to max_recv_sge == 1: the entry is freed and read by\nthe same call, and the freeing frame is smc_llc_srv_add_link() itself.\n\n [ 2.523161] BUG: KASAN: slab-use-after-free in smc_llc_save_add_link_rkeys+0x333/0x350\n [ 2.523499] Read of size 2 at addr ffff8880052194de by task kworker/0:1/11\n [ 2.523789]\n [ 2.523862] CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted 7.2.0-rc5-p0-g2c9dd296545d #35 PREEMPT(lazy)\n [ 2.523865] 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 [ 2.523866] Workqueue: smc_hs_wq smc_listen_work\n [ 2.523869] Call Trace:\n [ 2.523870] \n [ 2.523871] dump_stack_lvl+0x53/0x70\n [ 2.523872] print_report+0xd0/0x630\n [ 2.523874] ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n [ 2.523876] ? smc_llc_save_add_link_rkeys+0x333/0x350\n [ 2.523878] kasan_report+0xce/0x100\n [ 2.523879] ? smc_llc_save_add_link_rkeys+0x333/0x350\n [ 2.523881] smc_llc_save_add_link_rkeys+0x333/0x350\n [ 2.523883] ? smcr_buf_reg_lgr+0x2a4/0x660\n [ 2.523885] smc_llc_srv_add_link+0xaa2/0x1e50\n [ 2.523888] ? _printk+0xba/0xf0\n [ 2.523897] ? __pfx_smc_llc_srv_add_link+0x10/0x10\n [ 2.523899] ? down_write+0xb0/0x130\n [ 2.523903] ? __pfx_down_write+0x10/0x10\n [ 2.523905] smc_listen_work+0x489e/0x4d00\n [ 2.523907] ? kmem_cache_free+0x1c6/0x3a0\n [ 2.523911] ? __pfx_smc_listen_work+0x10/0x10\n [ 2.523913] ? release_sock+0x148/0x1d0\n [ 2.523915] ? smc_tcp_listen_work+0xb4f/0xfc0\n [ 2.523917] ? _raw_spin_lock_irq+0x80/0xe0\n [ 2.523918] ? __pfx__raw_spin_lock_irq+0x10/0x10\n [ 2.523920] process_one_work+0x633/0x1030\n [ 2.523922] ? assign_work+0x11d/0x370\n [ 2.523924] worker_thread+0x45b/0xd10\n [ 2.523926] ? __pfx_worker_thread+0x10/0x10\n [ 2.523928] ? __pfx_worker_thread+0x10/0x10\n [ 2.523929] kthread+0x2c6/0x3b0\n [ 2.523931] ? recalc_sigpending+0x15c/0x1e0\n [ 2.523934] ? __pfx_kthread+0x10/0x10\n [ 2.523935] ret_from_fork+0x36e/0x5a0\n [ 2.523937] ? __pfx_ret_from_fork+0x10/0x10\n [ 2.523938] ? __switch_to+0x572/0xdd0\n [ 2.523943] ? __pfx_kthread+0x10/0x10\n [ 2.523944] ret_from_fork_asm+0x1a/0x30\n [ 2.523947] \n [ 2.523948]\n [ 2.531253] Allocated by task 48:\n [ 2.531399] kasan_save_stack+0x33/0x60\n [ 2.531570] kasan_save_track+0x14/0x30\n [ 2.531737] __kasan_kmalloc+0x8f/0xa0\n [ 2.531905] __kmalloc_cache_noprof+0x158/0x370\n [ 2.532100] smc_llc_enqueue+0x72/0x560\n [ 2.532268] smc_wr_rx_tasklet_fn+0x474/0xa80\n [ 2.532491] tasklet_action_common+0x20f/0x8a0\n [ 2.532714] handle_softirqs+0x18e/0x590\n [ 2.532886] do_softirq+0x3b/0x60\n [ 2.533036] __local_bh_enable_ip+0x61/0x70\n [ 2.533221] __alloc_skb+0x732/0x890\n [ 2.533384] rxe_init_packet+0x16b/0x4f0\n [ 2.533567] prepare_ack_packet+0xb8/0x830\n [ 2.533760] rxe_receiver+0x495/0x96e0\n [ 2.533933] do_work+0x144/0x470\n [ 2\n---truncated---","state":0,"publishedAt":"2026-09-11T19:42:41.543+00:00","modifiedAt":"2026-10-19T08:46:05.74+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/smc/smc_llc.c\"\n ],\n \"versions\": [\n {\n \"version\": \"27ef6a9981fe74191849966a6d5e0400a4008ab8\",\n \"lessThan\": \"c52a998a223e7e84333306996edec096178d1e95\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"27ef6a9981fe74191849966a6d5e0400a4008ab8\",\n \"lessThan\": \"adef84cc85d449ac28d2b4b4c49cf19619c56e27\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"27ef6a9981fe74191849966a6d5e0400a4008ab8\",\n \"lessThan\": \"a42a459ef0e54cb0c4b3e43e21cb0e658e664f64\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/smc/smc_llc.c\"\n ],\n \"versions\": [\n {\n \"version\": \"6.14\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"6.14\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.50\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.4\",\n \"lessThanOrEqual\": \"7.2.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.3\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/c52a998a223e7e84333306996edec096178d1e95","https://git.kernel.org/stable/c/adef84cc85d449ac28d2b4b4c49cf19619c56e27","https://git.kernel.org/stable/c/a42a459ef0e54cb0c4b3e43e21cb0e658e664f64"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80981","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80981","identifiers":["CVE-2026-80981"]},"retained":false,"historicalAffected":[]}],"coverage":[]}