CVE-2021-47649
udmabuf: validate ubuf->pagecount
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Description
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().
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory 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
References (6)
CVSS
- Attack Vector
- LOCAL
- Complexity
- LOW
- Privileges
- LOW
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- NONE
- Availability
- HIGH
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