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 copycompressedsegment 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 btrfsworkhelper [btrfs] kernel: RIP: 0010:lzodecompressbio (./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: ffff989a3be856c0 R08: 0000000000000000 R09: 0000000000000000 kernel: R10: 0000000000000000 R11: 0000000000001000 R12: ffff98996e6d8000 kernel: R13: 0000000000000008 R14: 0000000000001000 R15: 000841551d5c1000 kernel: FS: 0000000000000000(0000) GS:ffff98a09d640000(0000) knlGS:0000000000000000 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel: CR2: 00001e9f984d9ea8 CR3: 000000014971a000 CR4: 00000000003506e0 kernel: Call Trace: kernel: <TASK> kernel: endcompressedbioread (fs/btrfs/compression.c:104 fs/btrfs/compression.c:1363 fs/btrfs/compression.c:323) btrfs kernel: endworkqueuefn (fs/btrfs/disk-io.c:1923) btrfs kernel: btrfsworkhelper (fs/btrfs/async-thread.c:326) btrfs kernel: processonework (./arch/x86/include/asm/jumplabel.h:27 ./include/linux/jumplabel.h:212 ./include/trace/events/workqueue.h:108 kernel/workqueue.c:2312) kernel: workerthread (./include/linux/list.h:292 kernel/workqueue.c:2455) kernel: ? processonework (kernel/workqueue.c:2397) kernel: kthread (kernel/kthread.c:377) kernel: ? kthreadcompleteandexit (kernel/kthread.c:332) kernel: retfromfork (arch/x86/entry/entry64.S:301) kernel: </TASK>