Linux Kernel up to 5.19.3 virtblk_init_hctx use after free

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.19.3. It has been classified as critical. Affected is the function virtblk_init_hctx. Performing a manipulation results in use after free. This vulnerability is cataloged as CVE-2022-50064. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 5.19.3. This affects the function virtblk_init_hctx. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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().

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2022-50064 since 06/18/2025. The exploitability is told to be easy. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/30/2025).

Upgrading to version 5.19.4 eliminates this vulnerability. Applying the patch 2b54e14535bc34bf649372060d518ec9f2b893b3/8d12ec10292877751ee4463b11a63bd850bc09b5 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-1350). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Avamar
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.19.0
• 5.19.1
• 5.19.2
• 5.19.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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