CVE Published: 21/10/2024 |
CVE Updated: 19/11/2024 |
CVE Year: 2024 Source: Linux |
Vendor: Linux |
Product: Linux Status : PUBLISHED
CVE-2024-49983 Description
In the Linux kernel, the following vulnerability has been resolved:
ext4: drop ppath from ext4_ext_replay_update_ex() to avoid double-free
When calling ext4_force_split_extent_at() in ext4_ext_replay_update_ex(),
the \'ppath\' is updated but it is the \'path\' that is freed, thus potentially
triggering a double-free in the following process:
ext4_ext_replay_update_ex
ppath = path
ext4_force_split_extent_at(&ppath)
ext4_split_extent_at
ext4_ext_insert_extent
ext4_ext_create_new_leaf
ext4_ext_grow_indepth
ext4_find_extent
if (depth > path[0].p_maxdepth)
kfree(path) ---> path First freed
*orig_path = path = NULL ---> null ppath
kfree(path) ---> path double-free !!!
So drop the unnecessary ppath and use path directly to avoid this problem.
And use ext4_find_extent() directly to update path, avoiding unnecessary
memory allocation and freeing. Also, propagate the error returned by
ext4_find_extent() instead of using strange error codes.