Linux Kernel up to 6.6.53/6.10.12/6.11.1 kernel/rcu/sync.c f2fs_handle_critical_error race condition

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.53/6.10.12/6.11.1. It has been declared as problematic. This vulnerability affects the function f2fs_handle_critical_error of the file kernel/rcu/sync.c. Such manipulation leads to race condition. This vulnerability is uniquely identified as CVE-2024-47689. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.53/6.10.12/6.11.1. It has been rated as problematic. Affected by this issue is the function f2fs_handle_critical_error of the file kernel/rcu/sync.c. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error() syzbot reports a f2fs bug as below: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 58 at kernel/rcu/sync.c:177 rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177 CPU: 1 UID: 0 PID: 58 Comm: kworker/1:2 Not tainted 6.10.0-syzkaller-12562-g1722389b0d86 #0 Workqueue: events destroy_super_work RIP: 0010:rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177 Call Trace: percpu_free_rwsem+0x41/0x80 kernel/locking/percpu-rwsem.c:42 destroy_super_work+0xec/0x130 fs/super.c:282 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 As Christian Brauner pointed out [1]: the root cause is f2fs sets SB_RDONLY flag in internal function, rather than setting the flag covered w/ sb->s_umount semaphore via remount procedure, then below race condition causes this bug: - freeze_super() - sb_wait_write(sb, SB_FREEZE_WRITE) - sb_wait_write(sb, SB_FREEZE_PAGEFAULT) - sb_wait_write(sb, SB_FREEZE_FS) - f2fs_handle_critical_error - sb->s_flags |= SB_RDONLY - thaw_super - thaw_super_locked - sb_rdonly() is true, so it skips sb_freeze_unlock(sb, SB_FREEZE_FS) - deactivate_locked_super Since f2fs has almost the same logic as ext4 [2] when handling critical error in filesystem if it mounts w/ errors=remount-ro option: - set CP_ERROR_FLAG flag which indicates filesystem is stopped - record errors to superblock - set SB_RDONLY falg Once we set CP_ERROR_FLAG flag, all writable interfaces can detect the flag and stop any further updates on filesystem. So, it is safe to not set SB_RDONLY flag, let's remove the logic and keep in line w/ ext4 [3]. [1] https://lore.kernel.org/all/20240729-himbeeren-funknetz-96e62f9c7aee@brauner [2] https://lore.kernel.org/all/20240729132721.hxih6ehigadqf7wx@quack3 [3] https://lore.kernel.org/linux-ext4/[email protected]

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2024-47689 since 09/30/2024. The exploitation is known to be difficult. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 216493 (Ubuntu 24.10 : Linux kernel vulnerabilities (USN-7276-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.54, 6.10.13 or 6.11.2 eliminates this vulnerability. Applying the patch 649ec8b30df1/de43021c7299/1f63f405c1a1/930c6ab93492 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (216493) and CERT Bund (WID-SEC-2024-3251). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• NetApp StorageGRID
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Kyocera Printer
• NetApp AFF
• NetApp ActiveIQ Unified Manager
• SUSE openSUSE
• IBM Security Guardium
• RESF Rocky Linux
• Dell NetWorker
• Dell Avamar
• IBM QRadar SIEM
• NetApp FAS
• SolarWinds Security Event Manager
• Dell PowerProtect Data Domain
• Open Source Linux Kernel
• Dell PowerScale OneFS

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.6.39
• 6.6.40
• 6.6.41
• 6.6.42
• 6.6.43
• 6.6.44
• 6.6.45
• 6.6.46
• 6.6.47
• 6.6.48
• 6.6.49
• 6.6.50
• 6.6.51
• 6.6.52
• 6.6.53
• 6.10.0
• 6.10.1
• 6.10.2
• 6.10.3
• 6.10.4
• 6.10.5
• 6.10.6
• 6.10.7
• 6.10.8
• 6.10.9
• 6.10.10
• 6.10.11
• 6.10.12
• 6.11.0
• 6.11.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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