{"id":"CVE-2026-23427","summary":"ksmbd: fix use-after-free in durable v2 replay of active file handles","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in durable v2 replay of active file handles\n\nparse_durable_handle_context() unconditionally assigns dh_info-\u003efp-\u003econn\nto the current connection when handling a DURABLE_REQ_V2 context with\nSMB2_FLAGS_REPLAY_OPERATION. ksmbd_lookup_fd_cguid() does not filter by\nfp-\u003econn, so it returns file handles that are already actively connected.\nThe unconditional overwrite replaces fp-\u003econn, and when the overwriting\nconnection is subsequently freed, __ksmbd_close_fd() dereferences the\nstale fp-\u003econn via spin_lock(&fp-\u003econn-\u003ellist_lock), causing a\nuse-after-free.\n\nKASAN report:\n\n[    7.349357] ==================================================================\n[    7.349607] BUG: KASAN: slab-use-after-free in _raw_spin_lock+0x75/0xe0\n[    7.349811] Write of size 4 at addr ffff8881056ac18c by task kworker/1:2/108\n[    7.350010]\n[    7.350064] CPU: 1 UID: 0 PID: 108 Comm: kworker/1:2 Not tainted 7.0.0-rc3+ #58 PREEMPTLAZY\n[    7.350068] 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[    7.350070] Workqueue: ksmbd-io handle_ksmbd_work\n[    7.350083] Call Trace:\n[    7.350087]  \u003cTASK\u003e\n[    7.350087]  dump_stack_lvl+0x64/0x80\n[    7.350094]  print_report+0xce/0x660\n[    7.350100]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n[    7.350101]  ? __pfx___mod_timer+0x10/0x10\n[    7.350106]  ? _raw_spin_lock+0x75/0xe0\n[    7.350108]  kasan_report+0xce/0x100\n[    7.350109]  ? _raw_spin_lock+0x75/0xe0\n[    7.350114]  kasan_check_range+0x105/0x1b0\n[    7.350116]  _raw_spin_lock+0x75/0xe0\n[    7.350118]  ? __pfx__raw_spin_lock+0x10/0x10\n[    7.350119]  ? __call_rcu_common.constprop.0+0x25e/0x780\n[    7.350125]  ? close_id_del_oplock+0x2cc/0x4e0\n[    7.350128]  __ksmbd_close_fd+0x27f/0xaf0\n[    7.350131]  ksmbd_close_fd+0x135/0x1b0\n[    7.350133]  smb2_close+0xb19/0x15b0\n[    7.350142]  ? __pfx_smb2_close+0x10/0x10\n[    7.350143]  ? xas_load+0x18/0x270\n[    7.350146]  ? _raw_spin_lock+0x84/0xe0\n[    7.350148]  ? __pfx__raw_spin_lock+0x10/0x10\n[    7.350150]  ? _raw_spin_unlock+0xe/0x30\n[    7.350151]  ? ksmbd_smb2_check_message+0xeb2/0x24c0\n[    7.350153]  ? ksmbd_tree_conn_lookup+0xcd/0xf0\n[    7.350154]  handle_ksmbd_work+0x40f/0x1080\n[    7.350156]  process_one_work+0x5fa/0xef0\n[    7.350162]  ? assign_work+0x122/0x3e0\n[    7.350163]  worker_thread+0x54b/0xf70\n[    7.350165]  ? __pfx_worker_thread+0x10/0x10\n[    7.350166]  kthread+0x346/0x470\n[    7.350170]  ? recalc_sigpending+0x19b/0x230\n[    7.350176]  ? __pfx_kthread+0x10/0x10\n[    7.350178]  ret_from_fork+0x4fb/0x6c0\n[    7.350183]  ? __pfx_ret_from_fork+0x10/0x10\n[    7.350185]  ? __switch_to+0x36c/0xbe0\n[    7.350188]  ? __pfx_kthread+0x10/0x10\n[    7.350190]  ret_from_fork_asm+0x1a/0x30\n[    7.350197]  \u003c/TASK\u003e\n[    7.350197]\n[    7.355160] Allocated by task 123:\n[    7.355261]  kasan_save_stack+0x33/0x60\n[    7.355373]  kasan_save_track+0x14/0x30\n[    7.355484]  __kasan_kmalloc+0x8f/0xa0\n[    7.355593]  ksmbd_conn_alloc+0x44/0x6d0\n[    7.355711]  ksmbd_kthread_fn+0x243/0xd70\n[    7.355839]  kthread+0x346/0x470\n[    7.355942]  ret_from_fork+0x4fb/0x6c0\n[    7.356051]  ret_from_fork_asm+0x1a/0x30\n[    7.356164]\n[    7.356214] Freed by task 134:\n[    7.356305]  kasan_save_stack+0x33/0x60\n[    7.356416]  kasan_save_track+0x14/0x30\n[    7.356527]  kasan_save_free_info+0x3b/0x60\n[    7.356646]  __kasan_slab_free+0x43/0x70\n[    7.356761]  kfree+0x1ca/0x430\n[    7.356862]  ksmbd_tcp_disconnect+0x59/0xe0\n[    7.356993]  ksmbd_conn_handler_loop+0x77e/0xd40\n[    7.357138]  kthread+0x346/0x470\n[    7.357240]  ret_from_fork+0x4fb/0x6c0\n[    7.357350]  ret_from_fork_asm+0x1a/0x30\n[    7.357463]\n[    7.357513] The buggy address belongs to the object at ffff8881056ac000\n[    7.357513]  which belongs to the cache kmalloc-1k of size 1024\n[    7.357857] The buggy address is located 396 bytes inside of\n[    7.357857]  freed 1024-byte region \n---truncated---","modified":"2026-05-18T05:58:35.005753057Z","published":"2026-04-03T15:15:14.183Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23427.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/568a25fd7bcdfb2790f7d42aa2a440dca4435c96"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9b0792c3eacf01e67f356d6ef9707b0ae5022419"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a5828c14a9e3d5eeed0bcc0a58f0f3fbca0cdcb2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b0158d9d6f4ec5941e49a0b812735db2844f9975"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b425e4d0eb321a1116ddbf39636333181675d8f4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23427.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23427"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8df4bcdb0a4232192b2445256c39b787d58ef14d"},{"fixed":"b0158d9d6f4ec5941e49a0b812735db2844f9975"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c8efcc786146a951091588e5fa7e3c754850cb3c"},{"fixed":"568a25fd7bcdfb2790f7d42aa2a440dca4435c96"},{"fixed":"a5828c14a9e3d5eeed0bcc0a58f0f3fbca0cdcb2"},{"fixed":"9b0792c3eacf01e67f356d6ef9707b0ae5022419"},{"fixed":"b425e4d0eb321a1116ddbf39636333181675d8f4"}]}],"versions":["v6.6.129","v6.6.128","v6.6.127","v6.6.126","v6.6.125","v6.6.124","v6.6.123","v6.6.122","v6.6.121","v6.6.120","v6.6.119","v6.6.118","v6.6.117","v6.6.116","v6.6.115","v6.6.114","v6.6.113","v6.6.112","v6.6.111","v6.6.110","v6.6.109","v6.6.108","v6.6.107","v6.6.106","v6.6.105","v6.6.104","v6.6.103","v6.6.102","v6.6.101","v6.6.100","v6.6.99","v6.6.98","v6.6.97","v6.6.96","v6.6.95","v6.6.94","v6.6.93","v6.6.92","v6.6.91","v6.6.90","v6.6.89","v6.6.88","v6.6.87","v6.6.86","v6.6.85","v6.6.84","v6.6.83","v6.6.82","v6.6.81","v6.6.80","v6.6.79","v6.6.78","v6.6.77","v6.6.76","v6.6.75","v6.6.74","v6.6.73","v6.6.72","v6.6.71","v6.6.70","v6.6.69","v6.6.68","v6.6.67","v6.6.66","v6.6.65","v6.6.64","v6.6.63","v6.6.62","v6.6.61","v6.6.60","v6.6.59","v6.6.58","v6.6.57","v6.6.56","v6.6.55","v6.6.54","v6.6.53","v6.6.52","v6.6.51","v6.6.50","v6.6.49","v6.6.48","v6.6.47","v6.6.46","v6.6.45","v6.6.44","v6.6.43","v6.6.42","v6.6.41","v6.6.40","v6.6.39","v6.6.38","v6.6.37","v6.6.36","v6.6.35","v6.6.34","v6.6.33","v6.6.32"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23427.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.130"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.78"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.9.0"},{"fixed":"6.18.20"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.19.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23427.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}