{"id":"CVE-2022-48919","state":"PUBLISHED","title":"cifs: fix double free race when mount fails in cifs_get_root()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix double free race when mount fails in cifs_get_root()\n\nWhen cifs_get_root() fails during cifs_smb3_do_mount() we call\ndeactivate_locked_super() which eventually will call delayed_free() which\nwill free the context.\nIn this situation we should not proceed to enter the out: section in\ncifs_smb3_do_mount() and free the same resources a second time.\n\n[Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60\n[Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0\n\n[Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G           OE     5.17.0-rc3+ #4\n[Thu Feb 10 12:59:06 2022] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019\n[Thu Feb 10 12:59:06 2022] Call Trace:\n[Thu Feb 10 12:59:06 2022]  <IRQ>\n[Thu Feb 10 12:59:06 2022]  dump_stack_lvl+0x5d/0x78\n[Thu Feb 10 12:59:06 2022]  print_address_description.constprop.0+0x24/0x150\n[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60\n[Thu Feb 10 12:59:06 2022]  kasan_report.cold+0x7d/0x117\n[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60\n[Thu Feb 10 12:59:06 2022]  __asan_load8+0x86/0xa0\n[Thu Feb 10 12:59:06 2022]  rcu_cblist_dequeue+0x32/0x60\n[Thu Feb 10 12:59:06 2022]  rcu_core+0x547/0xca0\n[Thu Feb 10 12:59:06 2022]  ? call_rcu+0x3c0/0x3c0\n[Thu Feb 10 12:59:06 2022]  ? __this_cpu_preempt_check+0x13/0x20\n[Thu Feb 10 12:59:06 2022]  ? lock_is_held_type+0xea/0x140\n[Thu Feb 10 12:59:06 2022]  rcu_core_si+0xe/0x10\n[Thu Feb 10 12:59:06 2022]  __do_softirq+0x1d4/0x67b\n[Thu Feb 10 12:59:06 2022]  __irq_exit_rcu+0x100/0x150\n[Thu Feb 10 12:59:06 2022]  irq_exit_rcu+0xe/0x30\n[Thu Feb 10 12:59:06 2022]  sysvec_hyperv_stimer0+0x9d/0xc0\n...\n[Thu Feb 10 12:59:07 2022] Freed by task 58179:\n[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50\n[Thu Feb 10 12:59:07 2022]  kasan_set_track+0x25/0x30\n[Thu Feb 10 12:59:07 2022]  kasan_set_free_info+0x24/0x40\n[Thu Feb 10 12:59:07 2022]  ____kasan_slab_free+0x137/0x170\n[Thu Feb 10 12:59:07 2022]  __kasan_slab_free+0x12/0x20\n[Thu Feb 10 12:59:07 2022]  slab_free_freelist_hook+0xb3/0x1d0\n[Thu Feb 10 12:59:07 2022]  kfree+0xcd/0x520\n[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0x149/0xbe0 [cifs]\n[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]\n[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140\n[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0\n[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210\n[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0\n[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n[Thu Feb 10 12:59:07 2022] Last potentially related work creation:\n[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50\n[Thu Feb 10 12:59:07 2022]  __kasan_record_aux_stack+0xb6/0xc0\n[Thu Feb 10 12:59:07 2022]  kasan_record_aux_stack_noalloc+0xb/0x10\n[Thu Feb 10 12:59:07 2022]  call_rcu+0x76/0x3c0\n[Thu Feb 10 12:59:07 2022]  cifs_umount+0xce/0xe0 [cifs]\n[Thu Feb 10 12:59:07 2022]  cifs_kill_sb+0xc8/0xe0 [cifs]\n[Thu Feb 10 12:59:07 2022]  deactivate_locked_super+0x5d/0xd0\n[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0xab9/0xbe0 [cifs]\n[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]\n[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140\n[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0\n[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210\n[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0\n[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae","publishedAt":"2024-08-22T01:32:43.390Z","updatedAt":"2026-08-05T08:52:54.791Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d17abdf7566566fc402c31899b353044a7ff3cf4","status":"affected","lessThan":"546d60859ecf13380fcabcbeace53a5971493a2b","versionType":"git"},{"version":"d17abdf7566566fc402c31899b353044a7ff3cf4","status":"affected","lessThan":"563431c1f3c8f2230e4a9c445fa23758742bc4f0","versionType":"git"},{"version":"d17abdf7566566fc402c31899b353044a7ff3cf4","status":"affected","lessThan":"3d6cc9898efdfb062efb74dc18cfc700e082f5d5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/cifs/cifsfs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.27","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16.13","status":"unaffected","lessThanOrEqual":"5.16.*","versionType":"semver"},{"version":"5.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/cifs/cifsfs.c"]}],"references":["https://git.kernel.org/stable/c/546d60859ecf13380fcabcbeace53a5971493a2b","https://git.kernel.org/stable/c/563431c1f3c8f2230e4a9c445fa23758742bc4f0","https://git.kernel.org/stable/c/3d6cc9898efdfb062efb74dc18cfc700e082f5d5"],"weaknesses":[],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/48xxx/CVE-2022-48919.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-48919","state":"PUBLISHED","datePublished":"2024-08-22T01:32:43.390Z","dateUpdated":"2026-08-05T08:52:54.791Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-08-21T06:06:23.295Z"},"containers":{"cna":{"title":"cifs: fix double free race when mount fails in cifs_get_root()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix double free race when mount fails in cifs_get_root()\n\nWhen cifs_get_root() fails during cifs_smb3_do_mount() we call\ndeactivate_locked_super() which eventually will call delayed_free() which\nwill free the context.\nIn this situation we should not proceed to enter the out: section in\ncifs_smb3_do_mount() and free the same resources a second time.\n\n[Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60\n[Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0\n\n[Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G           OE     5.17.0-rc3+ #4\n[Thu Feb 10 12:59:06 2022] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019\n[Thu Feb 10 12:59:06 2022] Call Trace:\n[Thu Feb 10 12:59:06 2022]  <IRQ>\n[Thu Feb 10 12:59:06 2022]  dump_stack_lvl+0x5d/0x78\n[Thu Feb 10 12:59:06 2022]  print_address_description.constprop.0+0x24/0x150\n[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60\n[Thu Feb 10 12:59:06 2022]  kasan_report.cold+0x7d/0x117\n[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60\n[Thu Feb 10 12:59:06 2022]  __asan_load8+0x86/0xa0\n[Thu Feb 10 12:59:06 2022]  rcu_cblist_dequeue+0x32/0x60\n[Thu Feb 10 12:59:06 2022]  rcu_core+0x547/0xca0\n[Thu Feb 10 12:59:06 2022]  ? call_rcu+0x3c0/0x3c0\n[Thu Feb 10 12:59:06 2022]  ? __this_cpu_preempt_check+0x13/0x20\n[Thu Feb 10 12:59:06 2022]  ? lock_is_held_type+0xea/0x140\n[Thu Feb 10 12:59:06 2022]  rcu_core_si+0xe/0x10\n[Thu Feb 10 12:59:06 2022]  __do_softirq+0x1d4/0x67b\n[Thu Feb 10 12:59:06 2022]  __irq_exit_rcu+0x100/0x150\n[Thu Feb 10 12:59:06 2022]  irq_exit_rcu+0xe/0x30\n[Thu Feb 10 12:59:06 2022]  sysvec_hyperv_stimer0+0x9d/0xc0\n...\n[Thu Feb 10 12:59:07 2022] Freed by task 58179:\n[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50\n[Thu Feb 10 12:59:07 2022]  kasan_set_track+0x25/0x30\n[Thu Feb 10 12:59:07 2022]  kasan_set_free_info+0x24/0x40\n[Thu Feb 10 12:59:07 2022]  ____kasan_slab_free+0x137/0x170\n[Thu Feb 10 12:59:07 2022]  __kasan_slab_free+0x12/0x20\n[Thu Feb 10 12:59:07 2022]  slab_free_freelist_hook+0xb3/0x1d0\n[Thu Feb 10 12:59:07 2022]  kfree+0xcd/0x520\n[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0x149/0xbe0 [cifs]\n[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]\n[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140\n[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0\n[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210\n[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0\n[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n[Thu Feb 10 12:59:07 2022] Last potentially related work creation:\n[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50\n[Thu Feb 10 12:59:07 2022]  __kasan_record_aux_stack+0xb6/0xc0\n[Thu Feb 10 12:59:07 2022]  kasan_record_aux_stack_noalloc+0xb/0x10\n[Thu Feb 10 12:59:07 2022]  call_rcu+0x76/0x3c0\n[Thu Feb 10 12:59:07 2022]  cifs_umount+0xce/0xe0 [cifs]\n[Thu Feb 10 12:59:07 2022]  cifs_kill_sb+0xc8/0xe0 [cifs]\n[Thu Feb 10 12:59:07 2022]  deactivate_locked_super+0x5d/0xd0\n[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0xab9/0xbe0 [cifs]\n[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]\n[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140\n[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0\n[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210\n[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0\n[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d17abdf7566566fc402c31899b353044a7ff3cf4","status":"affected","lessThan":"546d60859ecf13380fcabcbeace53a5971493a2b","versionType":"git"},{"version":"d17abdf7566566fc402c31899b353044a7ff3cf4","status":"affected","lessThan":"563431c1f3c8f2230e4a9c445fa23758742bc4f0","versionType":"git"},{"version":"d17abdf7566566fc402c31899b353044a7ff3cf4","status":"affected","lessThan":"3d6cc9898efdfb062efb74dc18cfc700e082f5d5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/cifs/cifsfs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.27","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16.13","status":"unaffected","lessThanOrEqual":"5.16.*","versionType":"semver"},{"version":"5.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/cifs/cifsfs.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/546d60859ecf13380fcabcbeace53a5971493a2b"},{"url":"https://git.kernel.org/stable/c/563431c1f3c8f2230e4a9c445fa23758742bc4f0"},{"url":"https://git.kernel.org/stable/c/3d6cc9898efdfb062efb74dc18cfc700e082f5d5"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable path is in the CIFS client during mount of a remote SMB share; a malicious SMB server can induce cifs_read_super()/cifs_get_root() failure after session/tree setup, triggering the buggy cleanup over the network.\nAC:L - A single failed mount through out_super deterministically double-frees prepath immediately and frees cifs_sb/ctx while an RCU delayed_free remains pending; the attacker fully controls the failing server responses and needs no uncontrolled race.\nPR:N - The attacker is the remote SMB server endpoint and needs no privileges on the victim client; client-side mount capability is part of the victim action, not attacker privilege.\nUI:R - A victim must mount or otherwise initiate a CIFS/SMB3 connection to the attacker-controlled share; the server cannot reach cifs_smb3_do_mount without that client action.\nS:U - The double-free/UAF impacts the local kernel CIFS client within the same security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - This is a use-after-free/double-free of cifs_sb and its smb3_fs_context, enabling heap reuse and arbitrary read primitives per UAF exploitation.\nI:H - The same double-free/UAF of heap objects (cifs_sb/ctx/prepath) enables heap spraying and arbitrary write or control-flow hijacking primitives.\nA:H - The bug produces a kernel use-after-free (KASAN report in rcu_cblist_dequeue) that can oops/panic the system even without full exploitation."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:52:54.791Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.27"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.16.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.17"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2022-48919","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T15:33:34.933209Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-12T17:33:11.259Z"}}]}}}