CVE-2024-47690

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

f2fs: get rid of online repaire on corrupted directory

syzbot reports a f2fs bug as below:

kernel BUG at fs/f2fs/inode.c:896! RIP: 0010:f2fs_evict_inode+0x1598/0x15c0 fs/f2fs/inode.c:896 Call Trace: evict+0x532/0x950 fs/inode.c:704 dispose_list fs/inode.c:747 [inline] evict_inodes+0x5f9/0x690 fs/inode.c:797 generic_shutdown_super+0x9d/0x2d0 fs/super.c:627 kill_block_super+0x44/0x90 fs/super.c:1696 kill_f2fs_super+0x344/0x690 fs/f2fs/super.c:4898 deactivate_locked_super+0xc4/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 task_work_run+0x24f/0x310 kernel/task_work.c:228 ptrace_notify+0x2d2/0x380 kernel/signal.c:2402 ptrace_report_syscall include/linux/ptrace.h:415 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] syscall_exit_work+0xc6/0x190 kernel/entry/common.c:173 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] syscall_exit_to_user_mode+0x279/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0010:f2fs_evict_inode+0x1598/0x15c0 fs/f2fs/inode.c:896

Online repaire on corrupted directory in f2fs_lookup() can generate dirty data/meta while racing w/ readonly remount, it may leave dirty inode after filesystem becomes readonly, however, checkpoint() will skips flushing dirty inode in a state of readonly mode, result in above panic.

Lets get rid of online repaire in f2fs_lookup(), and leave the work to fsck.f2fs.

Affected Software

References

• https://git.kernel.org/stable/c/884ee6dc85b959bc152f15bca80c30f06069e6c4
• https://git.kernel.org/stable/c/8be95cd607478d85fa4626e86f811e785905bcbf
• https://git.kernel.org/stable/c/bcefd0b0611f35b560d0a7281d87529fbe7a1e32
• https://git.kernel.org/stable/c/e8d64f598eeb079c42a52deaa3a91312c736a49d
• https://git.kernel.org/stable/c/f4746f2d79507f65cfbde11d3c39ee8338aa50af
• https://git.kernel.org/stable/c/f9ce2f550d53d044ecfb5ce996406cf42cd6b84d