diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2010-05-30 22:50:01 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-02 10:21:22 -0700 |
| commit | b47b979f9d5c199e34a32d3fbbe64a7fbf1ddcb2 (patch) | |
| tree | fc5598e198233ff5a7d53c521e3e04090d487662 | |
| parent | b6eaf5813482cd0f7a26be329845518100097181 (diff) | |
ext4: Avoid crashing on NULL ptr dereference on a filesystem error
commit f70f362b4a6fe47c239dbfb3efc0cc2c10e4f09c upstream (as of v2.6.34-git13)
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: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/ext4/extents.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index ee9e2abb047c..d985da0215c7 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3281,8 +3281,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, */ if (path[depth].p_ext == NULL && depth != 0) { ext4_error(inode->i_sb, __func__, "bad extent address " - "inode: %lu, iblock: %d, depth: %d", - inode->i_ino, iblock, depth); + "inode: %lu, iblock: %lu, depth: %d", + inode->i_ino, (unsigned long) iblock, depth); err = -EIO; goto out2; } @@ -3418,8 +3418,11 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, } else { WARN_ON(eh->eh_entries == 0); ext4_error(inode->i_sb, __func__, - "inode#%lu, eh->eh_entries = 0!", inode->i_ino); - } + "inode#%lu, eh->eh_entries = 0 and " + "EOFBLOCKS_FL set", inode->i_ino); + err = -EIO; + goto out2; + } } err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); if (err) { |