{ "schema_version": "1.6.1", "id": "RPI-CVE-2023-52751", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2023-52751" ], "published": "2024-05-21T15:34:20Z", "summary": "smb: client: fix use-after-free in smb2_query_info_compound()", "details": "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 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.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt2", "1:6.1.47-1+rpt4", "1:6.1.54-1+rpt2", "1:6.1.58-1+rpt2", "1:6.1.63-1+rpt1", "1:6.1.73-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi2-rpi-v6", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7l", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v8", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-2712", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v6", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7l", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v8", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-2712", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v6", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7l", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v8", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-2712", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v6", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7l", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v8", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-2712", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v6", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7l", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v8", "binary_version": "1:6.1.73-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt2": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null }, "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null, "compiled_filter": false }, "1:6.1.54-1+rpt2": { "linux_commit": "2906f7abdc03d4a92b6b0e2e0c87ea2a9dffe8f7", "upstream_version": "6.1.54", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null }, "1:6.1.58-1+rpt2": { "linux_commit": "ccf1586ad0663fa91238ac56abf6340d6d740d18", "upstream_version": "6.1.58", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null }, "1:6.1.63-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.63", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": null }, "1:6.1.73-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.73", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": null } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2023-52751" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/6db94d08359c43f2c8fe372811cdee04564a41b9" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/93877b9afc2994c89362007aac480a7b150f386f" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/5c86919455c1edec99ebd3338ad213b59271a71b" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T11:24:39Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - Vulnerable code is in fs/smb/client/ and is reached via local VFS syscalls (fstatfs\u2192cifs_statfs\u2192smb2_queryfs\u2192smb2_query_info_compound\u2192open_cach ed_dir, also readdir/inode paths), not by an in-kernel SMB server accepting remote connections.\nAC:L - The attacker can drive both sides of the race\u2014hammering concurrent statfs/readdir on the mount while forcing directory lease breaks via a second SMB client (or a malicious server sending breaks right after the lease grant)\u2014so success does not depend on uncontrollable conditions.\nPR:L - Any unprivileged local user who can access an already-mounted CIFS/SMB3 share can invoke fstatfs/getdents on that path; no CAP_SYS_ADMIN or other elevated capability is required on the vulnerable path.\nUI:N - The attacker triggers the UAF solely through their own syscalls on a reachable mount; no separate victim action (such as opening a crafted file) is required in the worst reasonable deployment with a pre-mounted share.\nS:U - This is a standard in-kernel slab UAF enabling local privilege escalation within the same host kernel authority and does not cross a VM, IOMMU, or other security boundary.\nC:H - Use-after-free of the cached_fid heap object lets an attacker reclaim and control the freed slab contents, enabling arbitrary kernel memory disclosure primitives.\nI:H - The same UAF is exploitable via heap spraying into write/control-flow hijack primitives against kernel objects, enabling integrity compromise and code execution.\nA:H - The UAF causes a kernel oops/crash when the freed cached_fid is dereferenced (as shown by the KASAN slab-use-after-free report), fully denying availability even without further exploitation." } } }