From: Chao Yu <yuchao0@xxxxxxxxxx> [ Upstream commit 8b6810f8acfe429fde7c7dad4714692cc5f75651 ] As Jungyeon reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203219 - Overview When mounting the attached crafted image and running program, I got this error. Additionally, it hangs on sync after running the program. The image is intentionally fuzzed from a normal f2fs image for testing and I enabled option CONFIG_F2FS_CHECK_FS on. - Reproduces cc poc_06.c mkdir test mount -t f2fs tmp.img test cp a.out test cd test sudo ./a.out sync - Messages kernel BUG at fs/f2fs/node.c:1183! RIP: 0010:f2fs_remove_inode_page+0x294/0x2d0 Call Trace: 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 f2fs_remove_inode_page() will trigger kernel panic due to inconsistent i_blocks value of inode. To avoid panic, let's just print debug message and set SBI_NEED_FSCK to give a hint to fsck for latter repairing of potential image corruption. 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/node.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 3f99ab2886955..d45ecef751165 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1179,8 +1179,14 @@ int f2fs_remove_inode_page(struct inode *inode) f2fs_put_dnode(&dn); return -EIO; } - f2fs_bug_on(F2FS_I_SB(inode), - inode->i_blocks != 0 && inode->i_blocks != 8); + + if (unlikely(inode->i_blocks != 0 && inode->i_blocks != 8)) { + f2fs_msg(F2FS_I_SB(inode)->sb, KERN_WARNING, + "Inconsistent i_blocks, ino:%lu, iblocks:%llu", + inode->i_ino, + (unsigned long long)inode->i_blocks); + set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK); + } /* will put inode & node pages */ err = truncate_node(&dn); -- 2.20.1
