{"schema":"threatline.record/2","record":{"id":"CVE-2026-98815","aliases":[],"summary":"nvme: fix cdev lifetime","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvme: fix cdev lifetime\n\nSashiko bot reported a potential problem for the cdev lifetime in [0]\n- the code there is heavily based on the NVMe code.\n\nCurrently the NS head .open and .release file_operations methods take and\nput a reference to the nvme_ns_head to ensure that this structure does not\ndisappear while we open fds for that cdev.\n\nIn multipath mode, when we teardown the NS head, we call nvme_cdev_del() ->\ncdev_device_del() -> cdev_del(). However after cdev_del() returns, cdevs\nalready open will remain and their fops will still be callable. As such,\nwe can still reference the cdev after the nvme_ns_head reference count\ndrops to 0 (and is freed).\n\nThis can be shown with an application which delays between opening the cdev\nand issuing the ioctl while the NS head is being torn down:\n\n# ./ioctl_file /dev/ng1n1 &\n# waiting 10 seconds ....\n\n# ./ini_nvme_teardown.sh\n[   21.221718] nvme nvme1: Removing ctrl: NQN \"nvme-test-target\"\n[   21.274609] nvme nvme2: Removing ctrl: NQN \"nvme-test-target\"\n# now going to issue ioctl ....\n[   26.549285] ==================================================================\n[   26.550841] BUG: KASAN: slab-use-after-free in cdev_put.part.0+0x3d/0x40\n[   26.552352] Read of size 8 at addr ffff88811e7fa170 by task ioctl_file/237\n[   26.553805]\n[   26.554227] CPU: 3 UID: 0 PID: 237 Comm: ioctl_file Not tainted 7.2.0-rc1-00004-g6852a10e32d4 #921 PREEMPT(lazy)\n[   26.554236] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   26.554241] Call Trace:\n[   26.554245]  <TASK>\n[   26.554248]  dump_stack_lvl+0x68/0xa0\n[   26.554266]  print_report+0x10d/0x5d0\n[   26.554276]  ? __virt_addr_valid+0x21d/0x3f0\n[   26.554287]  ? cdev_put.part.0+0x3d/0x40\n[   26.554292]  kasan_report+0x96/0xd0\n[   26.554300]  ? cdev_put.part.0+0x3d/0x40\n[   26.554307]  cdev_put.part.0+0x3d/0x40\n[   26.554313]  __fput+0x7bc/0xa70\n[   26.554322]  fput_close_sync+0xd8/0x190\n[   26.554328]  ? __pfx_fput_close_sync+0x10/0x10\n[   26.554337]  __x64_sys_close+0x79/0xd0\n[   26.554344]  do_syscall_64+0x117/0x6b0\n[   26.554351]  entry_SYSCALL_64_after_hwframe+0x77/0x7f\n[   26.554358] RIP: 0033:0x7f938c067727\n[   26.554364] Code: 48 89 fa 4c 89 df e8 28 ad 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5bf\n[   26.554369] RSP: 002b:00007fff49f05980 EFLAGS: 00000202 ORIG_RAX: 0000000000000003\n[   26.554376] RAX: ffffffffffffffda RBX: 00007f938bfd7780 RCX: 00007f938c067727\n[   26.554380] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003\n[   26.554383] RBP: 00007fff49f05a10 R08: 0000000000000000 R09: 0000000000000000\n[   26.554386] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000\n[   26.554389] R13: 00007fff49f05b40 R14: 00007f938c207000 R15: 000055c148471d78\n[   26.554397]  </TASK>\n[   26.554399]\n[   26.575612] Allocated by task 100:\n[   26.575871]  kasan_save_stack+0x24/0x50\n[   26.576157]  kasan_save_track+0x14/0x30\n[   26.576418]  __kasan_kmalloc+0x7f/0x90\n[   26.576668]  __kmalloc_noprof+0x281/0x6c0\n[   26.576938]  nvme_alloc_ns+0x7f7/0x3170\n[   26.577206]  nvme_scan_ns+0x508/0x880\n[   26.577449]  async_run_entry_fn+0x8c/0x350\n[   26.577723]  process_scheduled_works+0xb6f/0x1a00\n[   26.578034]  worker_thread+0x4ad/0xb40\n[   26.578283]  kthread+0x34f/0x450\n[   26.578501]  ret_from_fork+0x563/0x800\n[   26.578752]  ret_from_fork_asm+0x1a/0x30\n[   26.579012]\n[   26.579124] Freed by task 237:\n[   26.579335]  kasan_save_stack+0x24/0x50\n[   26.579596]  kasan_save_track+0x14/0x30\n[   26.579855]  kasan_save_free_info+0x3a/0x60\n[   26.580131]  __kasan_slab_free+0x43/0x70\n[   26.580388]  kfree+0x321/0x500\n[   26.580591]  nvme_ns_head_chr_release+0x39/0x50\n[   26.580883]  __fput+0x352/0xa70\n[   26.581095]  fput_close_sync+0xd8/0x190\n[   26.581350]  __x64_sys_close+0x79/0xd0\n[   26.581595]  do_syscall_64+0x117/0x6b0\n[   26.581842]  entry_SYSCAL\n---truncated---","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98815","source_modified_at":"2026-10-19T09:26:08.384Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"98b09ad7934482e64db4b4477d91e3bbf43adf4c","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"9952f3882ecba709092379b71e02b09762b26f96","status":"affected","versionType":"git"},{"version":"0","lessThan":"7.2.10","status":"affected","versionType":"semver"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98815","source_modified_at":"2026-10-19T09:26:08.384Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"7.2.10","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98815","source_modified_at":"2026-10-19T09:26:08.384Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"98b09ad7934482e64db4b4477d91e3bbf43adf4c","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98815","source_modified_at":"2026-10-19T09:26:08.384Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"9952f3882ecba709092379b71e02b09762b26f96","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98815","source_modified_at":"2026-10-19T09:26:08.384Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"7.2.10","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00198,"percentile":0.09009,"score_date":"2026-10-23"},"published_at":"2026-10-18T15:49:03.248Z","modified_at":"2026-10-19T09:26:08.384Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98815","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:26:08.384Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98815","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/98b09ad7934482e64db4b4477d91e3bbf43adf4c"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/9952f3882ecba709092379b71e02b09762b26f96"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:26:08.384Z","content_hash":"71b2fc9f1c77a8da424d85c44679bf00a64915d675e4c98f689006440077ebd7"}}