CVE-2022-50064
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: virtio-blk: Avoid use-after-free on suspend/resume hctx->user_data is set to vq in virtblk_init_hctx(). However, vq is freed on suspend and reallocated on resume. So, hctx->user_data is invalid after resume, and it will cause use-after-free accessing which will result in the kernel crash something like below: [ 22.428391] Call Trace: [ 22.428899] <TASK> [ 22.429339] virtqueue_add_split+0x3eb/0x620 [ 22.430035] ? __blk_mq_alloc_requests+0x17f/0x2d0 [ 22.430789] ? kvm_clock_get_cycles+0x14/0x30 [ 22.431496] virtqueue_add_sgs+0xad/0xd0 [ 22.432108] virtblk_add_req+0xe8/0x150 [ 22.432692] virtio_queue_rqs+0xeb/0x210 [ 22.433330] blk_mq_flush_plug_list+0x1b8/0x280 [ 22.434059] __blk_flush_plug+0xe1/0x140 [ 22.434853] blk_finish_plug+0x20/0x40 [ 22.435512] read_pages+0x20a/0x2e0 [ 22.436063] ? folio_add_lru+0x62/0xa0 [ 22.436652] page_cache_ra_unbounded+0x112/0x160 [ 22.437365] filemap_get_pages+0xe1/0x5b0 [ 22.437964] ? context_to_sid+0x70/0x100 [ 22.438580] ? sidtab_context_to_sid+0x32/0x400 [ 22.439979] filemap_read+0xcd/0x3d0 [ 22.440917] xfs_file_buffered_read+0x4a/0xc0 [ 22.441984] xfs_file_read_iter+0x65/0xd0 [ 22.442970] __kernel_read+0x160/0x2e0 [ 22.443921] bprm_execve+0x21b/0x640 [ 22.444809] do_execveat_common.isra.0+0x1a8/0x220 [ 22.446008] __x64_sys_execve+0x2d/0x40 [ 22.446920] do_syscall_64+0x37/0x90 [ 22.447773] entry_SYSCALL_64_after_hwframe+0x63/0xcd This patch fixes this issue by getting vq from vblk, and removes virtblk_init_hctx().
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7 | 7.8 | 7.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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