[U-Boot] [PATCH v3 03/13] ext4: Do not crash when trying to grow a directory using extents

Stefan Brüns
2016-08-28T20:42:28Z

The following command crashes u-boot:
./sandbox/u-boot -c 'i=0; host bind 0 ./sandbox/test/fs/3GB.ext4.img ;
while test $i -lt 200 ; do echo $i; setexpr i $i + 1;
ext4write host 0 0 /foobar${i} 0; done'

Previously, the code updated the direct_block even for extents, and
fortunately crashed before pushing garbage to the disk.

Signed-off-by: Stefan Br?ns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
---
fs/ext4/ext4_common.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

v2: unchanged
v3: Added Reviewed-by

diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index fd3522e..49d6465 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -448,8 +448,13 @@ restart:
sizeof(struct ext2_dirent) + padding_factor;
if ((fs->blksz - totalbytes - last_entry_dirlen) <
new_entry_byte_reqd) {
- printf("1st Block Full:Allocate new block\n");
+ printf("Last Block Full:Allocate new block\n");

+ if (le32_to_cpu(g_parent_inode->flags) &
+ EXT4_EXTENTS_FL) {
+ printf("Directory uses extents\n");
+ goto fail;
+ }
if (direct_blk_idx == INDIRECT_BLOCKS - 1) {
printf("Directory exceeds limit\n");
goto fail;
--
2.9.3