In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix reloc root cleanup in merge_reloc_roots()
If the root we got has zero root refs in its root item, we are resetting
the root's ->reloc_root without using barriers like we do everywhere else. Sashiko complained about this while reviewing another patch, and it's
correct (see the Link tag below). Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless
the root points to the reloc root we have.
Fix this by using clear_reloc_root(), which issues the memory barrier
after setting the root's ->reloc_root to NULL and before clearing the bit
BTRFS_ROOT_DEAD_RELOC_TREE from the root.
Attack Parameters
Attack Vector
Local
Requires local access
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
References 3
https://git.kernel.org/stable/c/63d6b1f04cd91c825329712aa526215ffa5d11ca
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/ab48583aa9948205ff9a6470e23dbff74c565e24
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b78fe9563e2d5ae47805f1e5dc722c91fd30e1f8
416baaa9-dc9f-4396-8d5f-8c081fb06d67