From ea6d7e72fea49402aa445345aade7a26b81732e3 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Mon, 15 Apr 2019 15:28:31 +0800 Subject: [PATCH] f2fs: fix to avoid panic in dec_valid_node_count() As Jungyeon reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203213 - Overview When mounting the attached crafted image and running program, I got this error. Additionally, it hangs on sync after running 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 mkdir test mount -t f2fs tmp.img test cp a.out test cd test sudo ./a.out sync kernel BUG at fs/f2fs/f2fs.h:2012! RIP: 0010:truncate_node+0x2c9/0x2e0 Call Trace: f2fs_truncate_xattr_node+0xa1/0x130 f2fs_remove_inode_page+0x82/0x2d0 f2fs_evict_inode+0x2a3/0x3a0 evict+0xba/0x180 __dentry_kill+0xbe/0x160 dentry_kill+0x46/0x180 dput+0xbb/0x100 do_renameat2+0x3c9/0x550 __x64_sys_rename+0x17/0x20 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The reason is dec_valid_node_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 [Jaegeuk Kim: fix build warning and add unlikely] Signed-off-by: Jaegeuk Kim --- fs/f2fs/f2fs.h | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 3a1e621b451a..43475794e232 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2029,7 +2029,6 @@ static inline void dec_valid_node_count(struct f2fs_sb_info *sbi, f2fs_bug_on(sbi, !sbi->total_valid_block_count); f2fs_bug_on(sbi, !sbi->total_valid_node_count); - f2fs_bug_on(sbi, !is_inode && !inode->i_blocks); sbi->total_valid_node_count--; sbi->total_valid_block_count--; @@ -2039,10 +2038,19 @@ static inline void dec_valid_node_count(struct f2fs_sb_info *sbi, spin_unlock(&sbi->stat_lock); - if (is_inode) + if (is_inode) { dquot_free_inode(inode); - else + } else { + if (unlikely(inode->i_blocks == 0)) { + f2fs_msg(sbi->sb, KERN_WARNING, + "Inconsistent i_blocks, ino:%lu, iblocks:%llu", + inode->i_ino, + (unsigned long long)inode->i_blocks); + set_sbi_flag(sbi, SBI_NEED_FSCK); + return; + } f2fs_i_blocks_write(inode, 1, false, true); + } } static inline unsigned int valid_node_count(struct f2fs_sb_info *sbi)