CVE-2021-47649
What it is
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().
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Analyzed
Affected
- Linux Kernel < 5.4.189
- Linux Kernel < 5.10.110
- Linux Kernel < 5.15.33
- Linux Kernel < 5.16.19
- Linux Kernel < 5.17.2
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-47649.md and follow it. Check whether this project is affected by CVE-2021-47649. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882
- https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9
- https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e
- https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9
- https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202
- https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0
References
- https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882
- https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9
- https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e
- https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9
- https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202
- https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0