[PATCH] ext3: avoid triggering ext3_error on bad NFS file handle

The inode number out of an NFS file handle gets passed eventually to
ext3_get_inode_block() without any checking.  If ext3_get_inode_block()
allows it to trigger an error, then bad filehandles can have unpleasant
effect - ext3_error() will usually cause a forced read-only remount, or a
panic if `errors=panic' was used.

So remove the call to ext3_error there and put a matching check in
ext3/namei.c where inode numbers are read off storage.

[akpm@osdl.org: fix off-by-one error]
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: <stable@kernel.org>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Eric Sandeen <esandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 6 deletions

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index f804d5e9d60c..ab034d3053ea 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -2402,14 +2402,15 @@ static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
         struct buffer_head *bh;
         struct ext3_group_desc * gdp;
 
-
-        if ((ino != EXT3_ROOT_INO && ino != EXT3_JOURNAL_INO &&
-                ino != EXT3_RESIZE_INO && ino < EXT3_FIRST_INO(sb)) ||
-                ino > le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count)) {
-                ext3_error(sb, "ext3_get_inode_block",
-                            "bad inode number: %lu", ino);
+        if (!ext3_valid_inum(sb, ino)) {
+                /*
+                 * This error is already checked for in namei.c unless we are
+                 * looking at an NFS filehandle, in which case no error
+                 * report is needed
+                 */
                 return 0;
         }
+
         block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
         if (block_group >= EXT3_SB(sb)->s_groups_count) {
                 ext3_error(sb,"ext3_get_inode_block","group >= groups count");