From: Josef Bacik <jbacik@redhat.com> Date: Mon, 20 Apr 2009 15:43:11 -0400 Subject: [fs] ext3: dir_index: error out on corrupt dx dirs Message-id: 1240256591-27409-1-git-send-email-jbacik@redhat.com O-Subject: [PATCH] [RHEL5.4] dir_index: error out instead of BUG on corrupt dx dirs Bugzilla: 454942 RH-Acked-by: Peter Staubach <staubach@redhat.com> RH-Acked-by: Eric Sandeen <sandeen@redhat.com> This is in reference to bz 454942, and is a backport of commit commit 3d82abae9523c33d4a16fdfdfd2bdde316d7b56a Author: Eric Sandeen <sandeen@redhat.com> Date: Tue Sep 18 22:46:38 2007 -0700 dir_index: error out instead of BUG on corrupt dx dirs Convert asserts (BUGs) in dx_probe from bad on-disk data to recoverable errors with helpful warnings. With help catching other asserts from Duane Griffin <duaneg@dghda.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Acked-by: Duane Griffin <duaneg@dghda.com> Acked-by: Theodore Ts'o <tytso@mit.edu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> This was tested with the corrupted image provided in the bz and it fixed the problem. Signed-off-by: Josef Bacik <jbacik@redhat.com> diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c index 35590db..0bb4924 100644 --- a/fs/ext3/namei.c +++ b/fs/ext3/namei.c @@ -380,13 +380,28 @@ dx_probe(struct dentry *dentry, struct inode *dir, entries = (struct dx_entry *) (((char *)&root->info) + root->info.info_length); - assert(dx_get_limit(entries) == dx_root_limit(dir, - root->info.info_length)); + + if (dx_get_limit(entries) != dx_root_limit(dir, + root->info.info_length)) { + ext3_warning(dir->i_sb, __FUNCTION__, + "dx entry: limit != root limit"); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail; + } + dxtrace (printk("Look up %x", hash)); while (1) { count = dx_get_count(entries); - assert (count && count <= dx_get_limit(entries)); + if (!count || count > dx_get_limit(entries)) { + ext3_warning(dir->i_sb, __FUNCTION__, + "dx entry: no count or count > limit"); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail2; + } + p = entries + 1; q = entries + count - 1; while (p <= q) @@ -424,8 +439,15 @@ dx_probe(struct dentry *dentry, struct inode *dir, if (!(bh = ext3_bread (NULL,dir, dx_get_block(at), 0, err))) goto fail2; at = entries = ((struct dx_node *) bh->b_data)->entries; - assert (dx_get_limit(entries) == dx_node_limit (dir)); + if (dx_get_limit(entries) != dx_node_limit (dir)) { + ext3_warning(dir->i_sb, __FUNCTION__, + "dx entry: limit != node limit"); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail2; + } frame++; + frame->bh = NULL; } fail2: while (frame >= frame_in) { @@ -433,6 +455,10 @@ fail2: frame--; } fail: + if (*err == ERR_BAD_DX_DIR) + ext3_warning(dir->i_sb, __FUNCTION__, + "Corrupt dir inode %ld, running e2fsck is " + "recommended.", dir->i_ino); return NULL; }