From 485c26ec70f823f2a9cf45982b724893e53a859e Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 24 Apr 2009 13:43:20 -0400 Subject: ext4: Fix softlockup caused by illegal i_file_acl value in on-disk inode If the block containing external extended attributes (which is stored in i_file_acl and i_file_acl_high) is larger than the on-disk filesystem, the process which tried to access the extended attributes will endlessly issue kernel printks complaining that "__find_get_block_slow() failed", locking up that CPU until the system is forcibly rebooted. So when we read in the inode, make sure the i_file_acl value is legal, and if not, flag the filesystem as being corrupted. Signed-off-by: "Theodore Ts'o" --- fs/ext4/inode.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c6bd6ced3bb..cab75bbcd57 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4409,7 +4409,17 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; } - if (ei->i_flags & EXT4_EXTENTS_FL) { + if (ei->i_file_acl && + ((ei->i_file_acl < + (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) + + EXT4_SB(sb)->s_gdb_count)) || + (ei->i_file_acl >= ext4_blocks_count(EXT4_SB(sb)->s_es)))) { + ext4_error(sb, __func__, + "bad extended attribute block %llu in inode #%lu", + ei->i_file_acl, inode->i_ino); + ret = -EIO; + goto bad_inode; + } else if (ei->i_flags & EXT4_EXTENTS_FL) { /* Validate extent which is part of inode */ ret = ext4_ext_check_inode(inode); } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || -- cgit v1.2.3