aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ext4/extents.c
diff options
context:
space:
mode:
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/extents.c
parent12e9b892002d9af057655d35b44db8ee9243b0dc (diff)
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/extents.c')
-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,
3370 */ 3370 */
3371 if (unlikely(path[depth].p_ext == NULL && depth != 0)) { 3371 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
3372 EXT4_ERROR_INODE(inode, "bad extent address " 3372 EXT4_ERROR_INODE(inode, "bad extent address "
3373 "iblock: %d, depth: %d pblock %lld", 3373 "lblock: %lu, depth: %d pblock %lld",
3374 map->m_lblk, depth, path[depth].p_block); 3374 (unsigned long) map->m_lblk, depth,
3375 path[depth].p_block);
3375 err = -EIO; 3376 err = -EIO;
3376 goto out2; 3377 goto out2;
3377 } 3378 }
@@ -3501,8 +3502,8 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3501 if (unlikely(ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))) { 3502 if (unlikely(ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))) {
3502 if (unlikely(!eh->eh_entries)) { 3503 if (unlikely(!eh->eh_entries)) {
3503 EXT4_ERROR_INODE(inode, 3504 EXT4_ERROR_INODE(inode,
3504 "eh->eh_entries == 0 ee_block %d", 3505 "eh->eh_entries == 0 and "
3505 ex->ee_block); 3506 "EOFBLOCKS_FL set");
3506 err = -EIO; 3507 err = -EIO;
3507 goto out2; 3508 goto out2;
3508 } 3509 }