[ Upstream commit 5e159cd349bf3a31fb7e35c23a93308eb30f4f71 ] As Jungyeon reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203209 - Overview When mounting the attached crafted image and running program, I got this error. Additionally, it hangs on sync after the this script. The image is intentionally fuzzed from a normal f2fs image for testing and I enabled option CONFIG_F2FS_CHECK_FS on. - Reproduces cc poc_01.c ./run.sh f2fs sync kernel BUG at fs/f2fs/f2fs.h:1788! RIP: 0010:f2fs_truncate_data_blocks_range+0x342/0x350 Call Trace: f2fs_truncate_blocks+0x36d/0x3c0 f2fs_truncate+0x88/0x110 f2fs_setattr+0x3e1/0x460 notify_change+0x2da/0x400 do_truncate+0x6d/0xb0 do_sys_ftruncate+0xf1/0x160 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The reason is dec_valid_block_count() will trigger kernel panic due to inconsistent count in between inode.i_blocks and actual block. To avoid panic, let's just print debug message and set SBI_NEED_FSCK to give a hint to fsck for latter repairing. Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx> [Jaegeuk Kim: fix build warning and add unlikely] Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/f2fs/f2fs.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 406d93b51a0b..6caae471c1a4 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1550,6 +1550,7 @@ enospc: return -ENOSPC; } +void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...); static inline void dec_valid_block_count(struct f2fs_sb_info *sbi, struct inode *inode, block_t count) @@ -1558,9 +1559,17 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi, spin_lock(&sbi->stat_lock); f2fs_bug_on(sbi, sbi->total_valid_block_count < (block_t) count); - f2fs_bug_on(sbi, inode->i_blocks < sectors); sbi->total_valid_block_count -= (block_t)count; spin_unlock(&sbi->stat_lock); + if (unlikely(inode->i_blocks < sectors)) { + f2fs_msg(sbi->sb, KERN_WARNING, + "Inconsistent i_blocks, ino:%lu, iblocks:%llu, sectors:%llu", + inode->i_ino, + (unsigned long long)inode->i_blocks, + (unsigned long long)sectors); + set_sbi_flag(sbi, SBI_NEED_FSCK); + return; + } f2fs_i_blocks_write(inode, count, false, true); } @@ -2382,7 +2391,6 @@ static inline void f2fs_update_iostat(struct f2fs_sb_info *sbi, bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr, int type); -void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...); static inline void verify_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr, int type) { -- 2.20.1
