1.5 KiB
CVE-2024-49889
Description
In the Linux kernel, the following vulnerability has been resolved:ext4: avoid use-after-free in ext4_ext_show_leaf()In ext4_find_extent(), path may be freed by error or be reallocated, sousing a previously saved *ppath may have been freed and thus may triggeruse-after-free, as follows:ext4_split_extent path = *ppath; ext4_split_extent_at(ppath) path = ext4_find_extent(ppath) ext4_split_extent_at(ppath) // ext4_find_extent fails to free path // but zeroout succeeds ext4_ext_show_leaf(inode, path) eh = path[depth].p_hdr // path use-after-free !!!Similar to ext4_split_extent_at(), we use *ppath directly as an input toext4_ext_show_leaf(). Fix a spelling error by the way.Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is onlyused in ext4_ext_show_leaf(), remove 'path' and use *ppath directly.This issue is triggered only when EXT_DEBUG is defined and therefore doesnot affect functionality.
POC
Reference
No PoCs from references.