Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug package and not the kernel-rt-debug package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

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>

• https://access.redhat.com/security/cve/CVE-2022-48923
• https://git.kernel.org/stable/c/741b23a970a79d5d3a1db2d64fa2c7b375a4febb
• https://git.kernel.org/stable/c/8df508b7a44cd8110c726057cd28e8f8116885eb
• https://git.kernel.org/stable/c/e326bd06cdde46df952361456232022298281d16