From: Qi Han hanqi@vivo.com
stable inclusion from stable-v6.6.66 commit 9669b28f81e0ec6305af7773846fbe2cef1e7d61 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEAPF CVE: CVE-2024-56586
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
--------------------------------
[ Upstream commit d5c367ef8287fb4d235c46a2f8c8d68715f3a0ca ]
creating a large files during checkpoint disable until it runs out of space and then delete it, then remount to enable checkpoint again, and then unmount the filesystem triggers the f2fs_bug_on as below:
------------[ cut here ]------------ kernel BUG at fs/f2fs/inode.c:896! CPU: 2 UID: 0 PID: 1286 Comm: umount Not tainted 6.11.0-rc7-dirty #360 Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:f2fs_evict_inode+0x58c/0x610 Call Trace: __die_body+0x15/0x60 die+0x33/0x50 do_trap+0x10a/0x120 f2fs_evict_inode+0x58c/0x610 do_error_trap+0x60/0x80 f2fs_evict_inode+0x58c/0x610 exc_invalid_op+0x53/0x60 f2fs_evict_inode+0x58c/0x610 asm_exc_invalid_op+0x16/0x20 f2fs_evict_inode+0x58c/0x610 evict+0x101/0x260 dispose_list+0x30/0x50 evict_inodes+0x140/0x190 generic_shutdown_super+0x2f/0x150 kill_block_super+0x11/0x40 kill_f2fs_super+0x7d/0x140 deactivate_locked_super+0x2a/0x70 cleanup_mnt+0xb3/0x140 task_work_run+0x61/0x90
The root cause is: creating large files during disable checkpoint period results in not enough free segments, so when writing back root inode will failed in f2fs_enable_checkpoint. When umount the file system after enabling checkpoint, the root inode is dirty in f2fs_evict_inode function, which triggers BUG_ON. The steps to reproduce are as follows:
dd if=/dev/zero of=f2fs.img bs=1M count=55 mount f2fs.img f2fs_dir -o checkpoint=disable:10% dd if=/dev/zero of=big bs=1M count=50 sync rm big mount -o remount,checkpoint=enable f2fs_dir umount f2fs_dir
Let's redirty inode when there is not free segments during checkpoint is disable.
Signed-off-by: Qi Han hanqi@vivo.com Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zizhi Wo wozizhi@huawei.com --- fs/f2fs/inode.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 0a9f17f1497b..437f48d8edcd 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -794,8 +794,10 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc) !is_inode_flag_set(inode, FI_DIRTY_INODE)) return 0;
- if (!f2fs_is_checkpoint_ready(sbi)) + if (!f2fs_is_checkpoint_ready(sbi)) { + f2fs_mark_inode_dirty_sync(inode, true); return -ENOSPC; + }
/* * We need to balance fs here to prevent from producing dirty node pages