udmabuf: validate ubuf->pagecount
Priority LOW 24Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: udmabuf: validate ubuf->pagecount Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The problem was in ubuf->pages == ZERO_PTR. ubuf->pagecount is calculated from arguments passed from user-space. If user creates udmabuf with list.size == 0 then ubuf->pagecount will be also equal to zero; it causes kmalloc_array() to return ZERO_PTR. Fix it by validating ubuf->pagecount before passing it to kmalloc_array().
Why it matters now
EPSS 0.00247 16th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.189, 5.10.110, 5.15.33 +3Red Hat: 2 advisoriesRed Hat: 5 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.20 and later | 5.4.189, 5.10.110, 5.15.33, 5.16.19, 5.17.2, 5.18 | Patch available | CNA |
- Linux VendorLinux Affected 4.20 and later Fixed in 5.4.189, 5.10.110, 5.15.33, 5.16.19, 5.17.2, 5.18 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.20 to before 5.4.189; 5.5 to before 5.10.110; 5.11 to before 5.15.33; 5.16 to before 5.16.19; 5.17 to before 5.17.2 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.20 to before 5.4.189; 5.5 to before 5.10.110; 5.11 to before 5.15.33; 5.16 to before 5.16.19; 5.17 to before 5.17.2 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.189, 5.10.110, 5.15.33, 5.16.19, 5.17.2, 5.18
Red Hat 2 advisories
- RHSA-2022:8267 Released 2022-11-15 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-162.6.1.el9_1
- Red Hat Enterprise Linux AppStream (v. 9) kernel-debug-devel-5.14.0-162.6.1.el9_1, kernel-debug-devel-matched-5.14.0-162.6.1.el9_1, kernel-devel-5.14.0-162.6.1.el9_1 +5
- Red Hat Enterprise Linux BaseOS (v. 9) bpftool-5.14.0-162.6.1.el9_1, kernel-5.14.0-162.6.1.el9_1, kernel-abi-stablelists-5.14.0-162.6.1.el9_1 +14
- RHSA-2022:7683 Released 2022-11-08 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-425.3.1.el8
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-425.3.1.el8, kernel-4.18.0-425.3.1.el8, kernel-abi-stablelists-4.18.0-425.3.1.el8 +19
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2022:7683 |
| Red Hat CodeReady Linux Builder (v. 9) | Fixed | RHSA-2022:8267 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2022:8267 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2022:7683 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2022:8267 |
Not affected: 4 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2021-47649
- 2026-10-03 Alias added: GHSA-cfjg-wwx3-vgp6
References
Patch 6
- https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9
- https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0
- https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e
- https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202
- https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9
- https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882
More Linux Kernel vulnerabilities
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- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2021-47649 · CVE Program
- CVE-2021-47649 · NVD
- FIRST EPSS
- GHSA-cfjg-wwx3-vgp6 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-47649 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences