# CVE-2024-49863: vhost/scsi: null-ptr-dereference in vhost_scsi_get_req() > A guest VM can trigger a null pointer dereference in the Linux kernel vhost/scsi driver, causing a denial of service by killing the vhost_worker process. - **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 21 Oct 2024 - **Updated:** 11 May 2026 - **Also known as:** AZL-51165, AZL-51288, BELL-CVE-2024-49863, DEBIAN-CVE-2024-49863, GHSA-f3gg-6f8f-39gh, UBUNTU-CVE-2024-49863 ## What is CVE-2024-49863? CVE-2024-49863 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 2024. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description In the Linux kernel, the following vulnerability has been resolved: vhost/scsi: null-ptr-dereference in vhost_scsi_get_req() Since commit 3f8ca2e115e5 ("vhost/scsi: Extract common handling code from control queue handler") a null pointer dereference bug can be triggered when guest sends an SCSI AN request. In vhost_scsi_ctl_handle_vq(), `vc.target` is assigned with `&v_req.tmf.lun[1]` within a switch-case block and is then passed to vhost_scsi_get_req() which extracts `vc->req` and `tpg`. However, for a `VIRTIO_SCSI_T_AN_*` request, tpg is not required, so `vc.target` is set to NULL in this branch. Later, in vhost_scsi_get_req(), `vc->target` is dereferenced without being checked, leading to a null pointer dereference bug. This bug can be triggered from guest. When this bug occurs, the vhost_worker process is killed while holding `vq->mutex` and the corresponding tpg will remain occupied indefinitely. Below is the KASAN report: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 840 Comm: poc Not tainted 6.10.0+ #1 Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:vhost_scsi_get_req+0x165/0x3a0 Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2b 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 65 30 4c 89 e2 48 c1 ea 03 <0f> b6 04 02 4c 89 e2 83 e2 07 38 d0 7f 08 84 c0 0f 85 be 01 00 00 RSP: 0018:ffff888017affb50 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88801b000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888017affcb8 RBP: ffff888017affb80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888017affc88 R14: ffff888017affd1c R15: ffff888017993000 FS: 000055556e076500(0000) GS:ffff88806b100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200027c0 CR3: 0000000010ed0004 CR4: 0000000000370ef0 Call Trace: ? show_regs+0x86/0xa0 ? die_addr+0x4b/0xd0 ? exc_general_protection+0x163/0x260 ? asm_exc_general_protection+0x27/0x30 ? vhost_scsi_get_req+0x165/0x3a0 vhost_scsi_ctl_handle_vq+0x2a4/0xca0 ? __pfx_vhost_scsi_ctl_handle_vq+0x10/0x10 ? __switch_to+0x721/0xeb0 ? __schedule+0xda5/0x5710 ? __kasan_check_write+0x14/0x30 ? _raw_spin_lock+0x82/0xf0 vhost_scsi_ctl_handle_kick+0x52/0x90 vhost_run_work_list+0x134/0x1b0 vhost_task_fn+0x121/0x350 ... ---[ end trace 0000000000000000 ]--- Let's add a check in vhost_scsi_get_req. [whitespace fixes] Weakness: CWE-476 (NULL Pointer Dereference) ## Which versions are affected by CVE-2024-49863? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2024-49863? Apply the vendor's patch. ## Is CVE-2024-49863 being exploited? There is no known exploitation of CVE-2024-49863 in the wild and no public exploit code. ## Other vulnerabilities in Linux kernel - [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild) - [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild) - [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild) - [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild) - [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-49863 and fix it if it is affected. What it is: CVE-2024-49863 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 2024. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-49863 in the wild and no public exploit code. Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-49863/ (Markdown: https://insights.sbomify.com/CVE-2024-49863/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-49863 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-49863 - OSV: https://osv.dev/vulnerability/CVE-2024-49863 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-49863/ Summaries are generated and may contain mistakes; the official description above is the record.