From: Theodore Ts'o Subject: [PATCH,STABLE 2.6.29 13/18] ext4: Fix softlockup caused by illegal i_file_acl value in on-disk inode Date: Tue, 2 Jun 2009 08:07:54 -0400 Message-ID: <1243944479-20574-13-git-send-email-tytso@mit.edu> References: <1243944479-20574-1-git-send-email-tytso@mit.edu> <1243944479-20574-2-git-send-email-tytso@mit.edu> <1243944479-20574-3-git-send-email-tytso@mit.edu> <1243944479-20574-4-git-send-email-tytso@mit.edu> <1243944479-20574-5-git-send-email-tytso@mit.edu> <1243944479-20574-6-git-send-email-tytso@mit.edu> <1243944479-20574-7-git-send-email-tytso@mit.edu> <1243944479-20574-8-git-send-email-tytso@mit.edu> <1243944479-20574-9-git-send-email-tytso@mit.edu> <1243944479-20574-10-git-send-email-tytso@mit.edu> <1243944479-20574-11-git-send-email-tytso@mit.edu> <1243944479-20574-12-git-send-email-tytso@mit.edu> Cc: linux-ext4@vger.kernel.org, Theodore Ts'o To: stable@kernel.org Return-path: Received: from thunk.org ([69.25.196.29]:33528 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751202AbZFBMIK (ORCPT ); Tue, 2 Jun 2009 08:08:10 -0400 In-Reply-To: <1243944479-20574-12-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: 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" (cherry picked from commit 485c26ec70f823f2a9cf45982b724893e53a859e) --- fs/ext4/inode.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c4f0e14..ec3457b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4351,6 +4351,18 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; } + 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; + } + if (S_ISREG(inode->i_mode)) { inode->i_op = &ext4_file_inode_operations; inode->i_fop = &ext4_file_operations; -- 1.6.3.1.1.g75fc.dirty