CVE-2022-48923

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: 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: end_compressed_bio_read (fs/btrfs/compression.c:104 fs/btrfs/compression.c:1363 fs/btrfs/compression.c:323) btrfs

kernel: end_workqueue_fn (fs/btrfs/disk-io.c:1923) btrfs

kernel: btrfs_work_helper (fs/btrfs/async-thread.c:326) btrfs

kernel: process_one_work (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:212 ./include/trace/events/workqueue.h:108 kernel/workqueue.c:2312)

kernel: worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2455)

kernel: ? process_one_work (kernel/workqueue.c:2397)

kernel: kthread (kernel/kthread.c:377)

kernel: ? kthread_complete_and_exit (kernel/kthread.c:332)

kernel: ret_from_fork (arch/x86/entry/entry_64.S:301)

kernel: </TASK>