{"id":"CVE-2023-52751","title":"smb: client: fix use-after-free in smb2_query_info_compound()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-after-free in smb2_query_info_compound()\n\nThe following UAF was triggered when running fstests generic/072 with\nKASAN enabled against Windows Serve…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 06c106e1e8568e840c946cc0222579e3d29dab8e","Linux >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 6db94d08359c43f2c8fe372811cdee04564a41b9","Linux >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 93877b9afc2994c89362007aac480a7b150f386f","Linux >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 5c86919455c1edec99ebd3338ad213b59271a71b","Linux 6.1"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2024-09-10T15:37:15.794672Z"},"published":"2024-05-21","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:17:20.902Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2023-52751","references":[{"url":"https://git.kernel.org/stable/c/06c106e1e8568e840c946cc0222579e3d29dab8e"},{"url":"https://git.kernel.org/stable/c/6db94d08359c43f2c8fe372811cdee04564a41b9"},{"url":"https://git.kernel.org/stable/c/93877b9afc2994c89362007aac480a7b150f386f"},{"url":"https://git.kernel.org/stable/c/5c86919455c1edec99ebd3338ad213b59271a71b"}],"tags":["cve.org"],"epss":0.00243,"epssPercentile":0.15576,"ingestedAt":"2026-11-03T11:43:15.782Z","slug":"CVE-2023-52751","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-after-free in smb2_query_info_compound()\n\nThe following UAF was triggered when running fstests generic/072 with\nKASAN enabled against Windows Server 2022 and mount options\n'multichannel,max_channels=2,vers=3.1.1,mfsymlinks,noperm'\n\n  BUG: KASAN: slab-use-after-free in smb2_query_info_compound+0x423/0x6d0 [cifs]\n  Read of size 8 at addr ffff888014941048 by task xfs_io/27534\n\n  CPU: 0 PID: 27534 Comm: xfs_io Not tainted 6.6.0-rc7 #1\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS\n  rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014\n  Call Trace:\n   dump_stack_lvl+0x4a/0x80\n   print_report+0xcf/0x650\n   ? srso_alias_return_thunk+0x5/0x7f\n   ? srso_alias_return_thunk+0x5/0x7f\n   ? __phys_addr+0x46/0x90\n   kasan_report+0xda/0x110\n   ? smb2_query_info_compound+0x423/0x6d0 [cifs]\n   ? smb2_query_info_compound+0x423/0x6d0 [cifs]\n   smb2_query_info_compound+0x423/0x6d0 [cifs]\n   ? __pfx_smb2_query_info_compound+0x10/0x10 [cifs]\n   ? srso_alias_return_thunk+0x5/0x7f\n   ? __stack_depot_save+0x39/0x480\n   ? kasan_save_stack+0x33/0x60\n   ? kasan_set_track+0x25/0x30\n   ? ____kasan_slab_free+0x126/0x170\n   smb2_queryfs+0xc2/0x2c0 [cifs]\n   ? __pfx_smb2_queryfs+0x10/0x10 [cifs]\n   ? __pfx___lock_acquire+0x10/0x10\n   smb311_queryfs+0x210/0x220 [cifs]\n   ? __pfx_smb311_queryfs+0x10/0x10 [cifs]\n   ? srso_alias_return_thunk+0x5/0x7f\n   ? __lock_acquire+0x480/0x26c0\n   ? lock_release+0x1ed/0x640\n   ? srso_alias_return_thunk+0x5/0x7f\n   ? do_raw_spin_unlock+0x9b/0x100\n   cifs_statfs+0x18c/0x4b0 [cifs]\n   statfs_by_dentry+0x9b/0xf0\n   fd_statfs+0x4e/0xb0\n   __do_sys_fstatfs+0x7f/0xe0\n   ? __pfx___do_sys_fstatfs+0x10/0x10\n   ? srso_alias_return_thunk+0x5/0x7f\n   ? lockdep_hardirqs_on_prepare+0x136/0x200\n   ? srso_alias_return_thunk+0x5/0x7f\n   do_syscall_64+0x3f/0x90\n   entry_SYSCALL_64_after_hwframe+0x6e/0xd8\n\n  Allocated by task 27534:\n   kasan_save_stack+0x33/0x60\n   kasan_set_track+0x25/0x30\n   __kasan_kmalloc+0x8f/0xa0\n   open_cached_dir+0x71b/0x1240 [cifs]\n   smb2_query_info_compound+0x5c3/0x6d0 [cifs]\n   smb2_queryfs+0xc2/0x2c0 [cifs]\n   smb311_queryfs+0x210/0x220 [cifs]\n   cifs_statfs+0x18c/0x4b0 [cifs]\n   statfs_by_dentry+0x9b/0xf0\n   fd_statfs+0x4e/0xb0\n   __do_sys_fstatfs+0x7f/0xe0\n   do_syscall_64+0x3f/0x90\n   entry_SYSCALL_64_after_hwframe+0x6e/0xd8\n\n  Freed by task 27534:\n   kasan_save_stack+0x33/0x60\n   kasan_set_track+0x25/0x30\n   kasan_save_free_info+0x2b/0x50\n   ____kasan_slab_free+0x126/0x170\n   slab_free_freelist_hook+0xd0/0x1e0\n   __kmem_cache_free+0x9d/0x1b0\n   open_cached_dir+0xff5/0x1240 [cifs]\n   smb2_query_info_compound+0x5c3/0x6d0 [cifs]\n   smb2_queryfs+0xc2/0x2c0 [cifs]\n\nThis is a race between open_cached_dir() and cached_dir_lease_break()\nwhere the cache entry for the open directory handle receives a lease\nbreak while creating it.  And before returning from open_cached_dir(),\nwe put the last reference of the new @cfid because of\n!@cfid->has_lease.\n\nBesides the UAF, while running xfstests a lot of missed lease breaks\nhave been noticed in tests that run several concurrent statfs(2) calls\non those cached fids\n\n  CIFS: VFS: \\\\w22-root1.gandalf.test No task to wake, unknown frame...\n  CIFS: VFS: \\\\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1...\n  CIFS: VFS: \\\\w22-root1.gandalf.test smb buf 00000000715bfe83 len 108\n  CIFS: VFS: Dump pending requests:\n  CIFS: VFS: \\\\w22-root1.gandalf.test No task to wake, unknown frame...\n  CIFS: VFS: \\\\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1...\n  CIFS: VFS: \\\\w22-root1.gandalf.test smb buf 000000005aa7316e len 108\n  ...\n\nTo fix both, in open_cached_dir() ensure that @cfid->has_lease is set\nright before sending out compounded request so that any potential\nlease break will be get processed by demultiplex thread while we're\nstill caching @cfid.  And, if open failed for some reason, re-check\n@cfid->has_lease to decide whether or not put lease reference.\n\n## Affected\n\n- `Linux >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 06c106e1e8568e840c946cc0222579e3d29dab8e`\n- `Linux >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 6db94d08359c43f2c8fe372811cdee04564a41b9`\n- `Linux >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 93877b9afc2994c89362007aac480a7b150f386f`\n- `Linux >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 5c86919455c1edec99ebd3338ad213b59271a71b`\n- `Linux 6.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}