f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error() 漏洞信息(CVE-2024-47689)

一、漏洞 CVE-2024-47689 基础信息

漏洞标题

F2FS文件系统f2fs_handle_critical_error()函数存在安全漏洞(CNNVD-202002-492)

来源：AIGC 神龙大模型

漏洞描述信息

N/A

来源：AIGC 神龙大模型

CVSS信息

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

来源：AIGC 神龙大模型

漏洞类别

对因果或异常条件的不恰当检查

来源：AIGC 神龙大模型

漏洞标题

f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error()

来源：美国国家漏洞数据库 NVD

漏洞描述信息

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-ext4/20240805201241.27286-1-jack@suse.cz

来源：美国国家漏洞数据库 NVD

CVSS信息

N/A

来源：美国国家漏洞数据库 NVD

漏洞类别

N/A

来源：美国国家漏洞数据库 NVD

漏洞标题

Linux kernel 安全漏洞

来源：中国国家信息安全漏洞库 CNNVD

漏洞描述信息

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于f2fs文件系统中对SB_RDONLY标志的错误设置。

来源：中国国家信息安全漏洞库 CNNVD

CVSS信息

N/A

来源：中国国家信息安全漏洞库 CNNVD

漏洞类别

其他

来源：中国国家信息安全漏洞库 CNNVD

二、漏洞 CVE-2024-47689 的公开POC

#	POC 描述	源链接	神龙链接

三、漏洞 CVE-2024-47689 的情报信息

标题： f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error() - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
神龙速读
标题： f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error() - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
神龙速读
标题： f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error() - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
神龙速读
标题： f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error() - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
神龙速读
https://nvd.nist.gov/vuln/detail/CVE-2024-47689