drm/edid: In connector_bad_edid() cap num_of_ext by num_blocks read
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: 3 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: drm/edid: In connector_bad_edid() cap num_of_ext by num_blocks read In commit e11f5bd8228f ("drm: Add support for DP 1.4 Compliance edid corruption test") the function connector_bad_edid() started assuming that the memory for the EDID passed to it was big enough to hold `edid[0x7e] + 1` blocks of data (1 extra for the base block). It completely ignored the fact that the function was passed `num_blocks` which indicated how much memory had been allocated for the EDID. Let's fix this by adding a bounds check. This is important for handling the case where there's an error in the first block of the EDID. In that case we will call connector_bad_edid() without having re-allocated memory based on `edid[0x7e]`.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.7 and later | 5.10.75, 5.14.14, 5.15 | Patch available | CNA |
- Linux VendorLinux Affected 5.7 and later Fixed in 5.10.75, 5.14.14, 5.15 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.7 to before 5.10.75; 5.11 to before 5.14.14 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* | 5.15 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* | 5.15 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* | 5.15 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* | 5.15 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* | 5.15 rc5 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.7 to before 5.10.75; 5.11 to before 5.14.14 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* Versions 5.15 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* Versions 5.15 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* Versions 5.15 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* Versions 5.15 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* Versions 5.15 rc5 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.75, 5.14.14, 5.15
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 2 products
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-47444
- 2026-10-03 Alias added: GHSA-969w-fmcp-j8rq
References
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- 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-2021-47444 · CVE Program
- CVE-2021-47444 · NVD
- FIRST EPSS
- GHSA-969w-fmcp-j8rq · GitHub Advisory Database · CC BY 4.0
- CVE-2021-47444 · Red Hat security data · CC BY 4.0
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