CVE-2023-52848

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to drop meta_inode's page cache in f2fs_put_super()

syzbot reports a kernel bug as below:

F2FS-fs (loop1): detect filesystem reference count leak during umount, type: 10, count: 1 kernel BUG at fs/f2fs/super.c:1639! CPU: 0 PID: 15451 Comm: syz-executor.1 Not tainted 6.5.0-syzkaller-09338-ge0152e7481c6 #0 RIP: 0010:f2fs_put_super+0xce1/0xed0 fs/f2fs/super.c:1639 Call Trace: generic_shutdown_super+0x161/0x3c0 fs/super.c:693 kill_block_super+0x3b/0x70 fs/super.c:1646 kill_f2fs_super+0x2b7/0x3d0 fs/f2fs/super.c:4879 deactivate_locked_super+0x9a/0x170 fs/super.c:481 deactivate_super+0xde/0x100 fs/super.c:514 cleanup_mnt+0x222/0x3d0 fs/namespace.c:1254 task_work_run+0x14d/0x240 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd

In f2fs_put_super(), it tries to do sanity check on dirty and IO reference count of f2fs, once there is any reference count leak, it will trigger panic.

The root case is, during f2fs_put_super(), if there is any IO error in f2fs_wait_on_all_pages(), we missed to truncate meta_inode's page cache later, result in panic, fix this case.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.