diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2010-05-16 23:00:00 -0400 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2011-01-06 18:07:37 -0500 |
| commit | 3a58dfe3e599ca8188bd80d982f03ef202860075 (patch) | |
| tree | 34563b5437267f2a383c971359344541fc373cb4 /fs/ext4 | |
| parent | bdb69261f2e22b63f5fb2fcbb0de1c3425b61acc (diff) | |
ext4: Avoid crashing on NULL ptr dereference on a filesystem error
commit f70f362b4a6fe47c239dbfb3efc0cc2c10e4f09c upstream.
If the EOFBLOCK_FL flag is set when it should not be and the inode is
zero length, then eh_entries is zero, and ex is NULL, so dereferencing
ex to print ex->ee_block causes a kernel OOPS in
ext4_ext_map_blocks().
On top of that, the error message which is printed isn't very helpful.
So we fix this by printing something more explanatory which doesn't
involve trying to print ex->ee_block.
Addresses-Google-Bug: #2655740
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/extents.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index a1d3f7c1e7ce..8e8a7a4eedff 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3381,8 +3381,9 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, */ if (unlikely(path[depth].p_ext == NULL && depth != 0)) { EXT4_ERROR_INODE(inode, "bad extent address " - "iblock: %d, depth: %d pblock %lld", - iblock, depth, path[depth].p_block); + "iblock: %lu, depth: %d pblock %lld", + (unsigned long) iblock, depth, + path[depth].p_block); err = -EIO; goto out2; } @@ -3512,8 +3513,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, if (unlikely(ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))) { if (unlikely(!eh->eh_entries)) { EXT4_ERROR_INODE(inode, - "eh->eh_entries == 0 ee_block %d", - ex->ee_block); + "eh->eh_entries == 0 and " + "EOFBLOCKS_FL set"); err = -EIO; goto out2; } |