CVE-2022-48919

cifs: fix double free race when mount fails in cifs_get_root()

Published Aug 22, 2024 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

cifs: fix double free race when mount fails in cifs_get_root()

When cifs_get_root() fails during cifs_smb3_do_mount() we call
deactivate_locked_super() which eventually will call delayed_free() which
will free the context.
In this situation we should not proceed to enter the out: section in
cifs_smb3_do_mount() and free the same resources a second time.

[Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0

[Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G OE 5.17.0-rc3+ #4
[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
[Thu Feb 10 12:59:06 2022] Call Trace:
[Thu Feb 10 12:59:06 2022] <IRQ>
[Thu Feb 10 12:59:06 2022] dump_stack_lvl+0x5d/0x78
[Thu Feb 10 12:59:06 2022] print_address_description.constprop.0+0x24/0x150
[Thu Feb 10 12:59:06 2022] ? rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022] kasan_report.cold+0x7d/0x117
[Thu Feb 10 12:59:06 2022] ? rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022] __asan_load8+0x86/0xa0
[Thu Feb 10 12:59:06 2022] rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022] rcu_core+0x547/0xca0
[Thu Feb 10 12:59:06 2022] ? call_rcu+0x3c0/0x3c0
[Thu Feb 10 12:59:06 2022] ? __this_cpu_preempt_check+0x13/0x20
[Thu Feb 10 12:59:06 2022] ? lock_is_held_type+0xea/0x140
[Thu Feb 10 12:59:06 2022] rcu_core_si+0xe/0x10
[Thu Feb 10 12:59:06 2022] __do_softirq+0x1d4/0x67b
[Thu Feb 10 12:59:06 2022] __irq_exit_rcu+0x100/0x150
[Thu Feb 10 12:59:06 2022] irq_exit_rcu+0xe/0x30
[Thu Feb 10 12:59:06 2022] sysvec_hyperv_stimer0+0x9d/0xc0
...
[Thu Feb 10 12:59:07 2022] Freed by task 58179:
[Thu Feb 10 12:59:07 2022] kasan_save_stack+0x26/0x50
[Thu Feb 10 12:59:07 2022] kasan_set_track+0x25/0x30
[Thu Feb 10 12:59:07 2022] kasan_set_free_info+0x24/0x40
[Thu Feb 10 12:59:07 2022] ____kasan_slab_free+0x137/0x170
[Thu Feb 10 12:59:07 2022] __kasan_slab_free+0x12/0x20
[Thu Feb 10 12:59:07 2022] slab_free_freelist_hook+0xb3/0x1d0
[Thu Feb 10 12:59:07 2022] kfree+0xcd/0x520
[Thu Feb 10 12:59:07 2022] cifs_smb3_do_mount+0x149/0xbe0 [cifs]
[Thu Feb 10 12:59:07 2022] smb3_get_tree+0x1a0/0x2e0 [cifs]
[Thu Feb 10 12:59:07 2022] vfs_get_tree+0x52/0x140
[Thu Feb 10 12:59:07 2022] path_mount+0x635/0x10c0
[Thu Feb 10 12:59:07 2022] __x64_sys_mount+0x1bf/0x210
[Thu Feb 10 12:59:07 2022] do_syscall_64+0x5c/0xc0
[Thu Feb 10 12:59:07 2022] entry_SYSCALL_64_after_hwframe+0x44/0xae

[Thu Feb 10 12:59:07 2022] Last potentially related work creation:
[Thu Feb 10 12:59:07 2022] kasan_save_stack+0x26/0x50
[Thu Feb 10 12:59:07 2022] __kasan_record_aux_stack+0xb6/0xc0
[Thu Feb 10 12:59:07 2022] kasan_record_aux_stack_noalloc+0xb/0x10
[Thu Feb 10 12:59:07 2022] call_rcu+0x76/0x3c0
[Thu Feb 10 12:59:07 2022] cifs_umount+0xce/0xe0 [cifs]
[Thu Feb 10 12:59:07 2022] cifs_kill_sb+0xc8/0xe0 [cifs]
[Thu Feb 10 12:59:07 2022] deactivate_locked_super+0x5d/0xd0
[Thu Feb 10 12:59:07 2022] cifs_smb3_do_mount+0xab9/0xbe0 [cifs]
[Thu Feb 10 12:59:07 2022] smb3_get_tree+0x1a0/0x2e0 [cifs]
[Thu Feb 10 12:59:07 2022] vfs_get_tree+0x52/0x140
[Thu Feb 10 12:59:07 2022] path_mount+0x635/0x10c0
[Thu Feb 10 12:59:07 2022] __x64_sys_mount+0x1bf/0x210
[Thu Feb 10 12:59:07 2022] do_syscall_64+0x5c/0xc0
[Thu Feb 10 12:59:07 2022] entry_SYSCALL_64_after_hwframe+0x44/0xae

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Metrics epss

{'score': 0.00039}

epss

{'score': 0.00035}

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:8::nfv
cpe:/o:redhat:enterprise_linux:8
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-415
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: cifs: fix double free race when mount fails in cifs_get_root() When cifs_get_root() fails during cifs_smb3_do_mount() we call deactivate_locked_super() which eventually will call delayed_free() which will free the context. In this situation we should not proceed to enter the out: section in cifs_smb3_do_mount() and free the same resources a second time. [Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0 [Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G OE 5.17.0-rc3+ #4 [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 [Thu Feb 10 12:59:06 2022] Call Trace: [Thu Feb 10 12:59:06 2022] <IRQ> [Thu Feb 10 12:59:06 2022] dump_stack_lvl+0x5d/0x78 [Thu Feb 10 12:59:06 2022] print_address_description.constprop.0+0x24/0x150 [Thu Feb 10 12:59:06 2022] ? rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] kasan_report.cold+0x7d/0x117 [Thu Feb 10 12:59:06 2022] ? rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] __asan_load8+0x86/0xa0 [Thu Feb 10 12:59:06 2022] rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] rcu_core+0x547/0xca0 [Thu Feb 10 12:59:06 2022] ? call_rcu+0x3c0/0x3c0 [Thu Feb 10 12:59:06 2022] ? __this_cpu_preempt_check+0x13/0x20 [Thu Feb 10 12:59:06 2022] ? lock_is_held_type+0xea/0x140 [Thu Feb 10 12:59:06 2022] rcu_core_si+0xe/0x10 [Thu Feb 10 12:59:06 2022] __do_softirq+0x1d4/0x67b [Thu Feb 10 12:59:06 2022] __irq_exit_rcu+0x100/0x150 [Thu Feb 10 12:59:06 2022] irq_exit_rcu+0xe/0x30 [Thu Feb 10 12:59:06 2022] sysvec_hyperv_stimer0+0x9d/0xc0 ... [Thu Feb 10 12:59:07 2022] Freed by task 58179: [Thu Feb 10 12:59:07 2022] kasan_save_stack+0x26/0x50 [Thu Feb 10 12:59:07 2022] kasan_set_track+0x25/0x30 [Thu Feb 10 12:59:07 2022] kasan_set_free_info+0x24/0x40 [Thu Feb 10 12:59:07 2022] ____kasan_slab_free+0x137/0x170 [Thu Feb 10 12:59:07 2022] __kasan_slab_free+0x12/0x20 [Thu Feb 10 12:59:07 2022] slab_free_freelist_hook+0xb3/0x1d0 [Thu Feb 10 12:59:07 2022] kfree+0xcd/0x520 [Thu Feb 10 12:59:07 2022] cifs_smb3_do_mount+0x149/0xbe0 [cifs] [Thu Feb 10 12:59:07 2022] smb3_get_tree+0x1a0/0x2e0 [cifs] [Thu Feb 10 12:59:07 2022] vfs_get_tree+0x52/0x140 [Thu Feb 10 12:59:07 2022] path_mount+0x635/0x10c0 [Thu Feb 10 12:59:07 2022] __x64_sys_mount+0x1bf/0x210 [Thu Feb 10 12:59:07 2022] do_syscall_64+0x5c/0xc0 [Thu Feb 10 12:59:07 2022] entry_SYSCALL_64_after_hwframe+0x44/0xae [Thu Feb 10 12:59:07 2022] Last potentially related work creation: [Thu Feb 10 12:59:07 2022] kasan_save_stack+0x26/0x50 [Thu Feb 10 12:59:07 2022] __kasan_record_aux_stack+0xb6/0xc0 [Thu Feb 10 12:59:07 2022] kasan_record_aux_stack_noalloc+0xb/0x10 [Thu Feb 10 12:59:07 2022] call_rcu+0x76/0x3c0 [Thu Feb 10 12:59:07 2022] cifs_umount+0xce/0xe0 [cifs] [Thu Feb 10 12:59:07 2022] cifs_kill_sb+0xc8/0xe0 [cifs] [Thu Feb 10 12:59:07 2022] deactivate_locked_super+0x5d/0xd0 [Thu Feb 10 12:59:07 2022] cifs_smb3_do_mount+0xab9/0xbe0 [cifs] [Thu Feb 10 12:59:07 2022] smb3_get_tree+0x1a0/0x2e0 [cifs] [Thu Feb 10 12:59:07 2022] vfs_get_tree+0x52/0x140 [Thu Feb 10 12:59:07 2022] path_mount+0x635/0x10c0 [Thu Feb 10 12:59:07 2022] __x64_sys_mount+0x1bf/0x210 [Thu Feb 10 12:59:07 2022] do_syscall_64+0x5c/0xc0 [Thu Feb 10 12:59:07 2022] entry_SYSCALL_64_after_hwframe+0x44/0xae
Title cifs: fix double free race when mount fails in cifs_get_root()
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Aug 5, 2026, 8:52 AM
Reserved
Aug 21, 2024, 6:06 AM
Status
Modified
Published
Aug 22, 2024, 2:15 AM
Modified
Aug 4, 2026, 10:17 AM
Severity
Moderate
Public date
Aug 22, 2024, 12:00 AM