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authorTheodore Ts'o <tytso@mit.edu>2010-05-16 23:00:00 -0400
committerTheodore Ts'o <tytso@mit.edu>2010-05-16 23:00:00 -0400
commitf70f362b4a6fe47c239dbfb3efc0cc2c10e4f09c (patch)
treeb9db08f3675d1cc0ed7d1af08418f5f5ba554ca6 /fs/ext4
parent12e9b892002d9af057655d35b44db8ee9243b0dc (diff)
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ext4: Avoid crashing on NULL ptr dereference on a filesystem error
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>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/extents.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 42d8ce91adbd..e40d2b793f2d 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3370,8 +3370,9 @@ int ext4_ext_map_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",
- map->m_lblk, depth, path[depth].p_block);
+ "lblock: %lu, depth: %d pblock %lld",
+ (unsigned long) map->m_lblk, depth,
+ path[depth].p_block);
err = -EIO;
goto out2;
}
@@ -3501,8 +3502,8 @@ int ext4_ext_map_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;
}