Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

btrfs: prevent copying too big compressed lzo segment

Compressed length can be corrupted to be a lot larger than memory we have allocated for buffer. This will cause memcpy in copy_compressed_segment to write outside of allocated memory.

This mostly results in stuck read syscall but sometimes when using btrfs send can get #GP

kernel: general protection fault, probably for non-canonical address 0x841551d5c1000: 0000 [#1] PREEMPT SMP NOPTI kernel: CPU: 17 PID: 264 Comm: kworker/u256:7 Tainted: P OE 5.17.0-rc2-1 #12 kernel: Workqueue: btrfs-endio btrfs_work_helper [btrfs] kernel: RIP: 0010:lzo_decompress_bio (./include/linux/fortify-string.h:225 fs/btrfs/lzo.c:322 fs/btrfs/lzo.c:394) btrfs Code starting with the faulting instruction =========================================== 0:* 48 8b 06 mov (%rsi),%rax <-- trapping instruction 3: 48 8d 79 08 lea 0x8(%rcx),%rdi 7: 48 83 e7 f8 and $0xfffffffffffffff8,%rdi b: 48 89 01 mov %rax,(%rcx) e: 44 89 f0 mov %r14d,%eax 11: 48 8b 54 06 f8 mov -0x8(%rsi,%rax,1),%rdx kernel: RSP: 0018:ffffb110812efd50 EFLAGS: 00010212 kernel: RAX: 0000000000001000 RBX: 000000009ca264c8 RCX: ffff98996e6d8ff8 kernel: RDX: 0000000000000064 RSI: 000841551d5c1000 RDI: ffffffff9500435d kernel: RBP: ffff989a3be856…