In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate inline xattrs during inode block validation
Patch series "ocfs2: validate xattr entry bounds", v7. This series validates OCFS2 xattr entry name/value bounds when xattr
metadata is read and validated, before getxattr() or listxattr() can walk
out-of-range entry arrays or offsets from corrupted metadata. This patch (of 2):
ocfs2_validate_inode_block() verifies a dinode before OCFS2 users walk
metadata from it, but inline xattr metadata is still checked only in
operation-specific consumers.
The existing ibody lookup helper validates
inline header placement and entry count, but inode block validation does
not reject entry name/value bounds. Add a flat xattr entry validator and call it from inode block validation
for inline xattrs. Keep the operation paths on their existing
header/count lookup checks; the full entry bounds check now runs when the
inode block is validated at read time.
Reject corrupted inline xattr metadata before ocfs2_xattr_ibody_get() or
listxattr() can walk past the inline storage. Validation reproduced this kernel report:
BUG: KASAN: use-after-free in ocfs2_xattr_find_entry+0x5a/0x170
Read of size 2 at addr ffff8881242a2000 by task python3/529
Call Trace:
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x630
kasan_report+0xe0/0x110
ocfs2_xattr_find_entry+0x5a/0x170
ocfs2_xattr_get_nolock+0x20a/0x820
ocfs2_xattr_get+0x10c/0x1e0
__vfs_getxattr+0xe2/0x130
vfs_getxattr+0x185/0x1b0
Характеристики атаки
Последствия
Строка CVSS v3.1