Medium [CVE-2026-63878] check num_entries in GEM_OP GET_MAPPING_INFO
This medium-severity Red Hat Linux advisory covers CVE-2026-63878 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9.
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Summary
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: check num_entries in GEM_OP GET_MAPPING_INFO kvcalloc(args->num_entries, sizeof(*vm_entries), GFP_KERNEL) at amdgpu_gem.c:1050 uses the user-supplied num_entries directly without any upper bounds check.
Since num_entries is a __u32 and sizeof(drm_amdgpu_gem_vm_entry) is 32 bytes, a large num_entries produces an allocation exceeding INT_MAX, triggering WARNING in __kvmalloc_node_noprof(), causing a kernel WARNING, TAINT_WARN, and panic on CONFIG_PANIC_ON_WARN=y systems.
Add a size bounds check before we invoke the kvzalloc() to reject oversized num_entries early with -EINVAL. (cherry picked from commit 1fe7bf5457f6efd7be60b17e23163ba54341d73d) A local attacker can exploit an integer overflow vulnerability by providing an excessively large value for the `num_entries` parameter in the `GEM_OP GET_MAPPING_INFO` ioctl.
This can lead to an attempt to allocate an extremely large amount of memory, resulting in a kernel warning, system taint, and potentially a system panic, causing a Denial of Service (DoS). Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
Weakness: CWE-190. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 9.
Will not fix / out of support: Red Hat Enterprise Linux 6.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 7 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 7 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 7 days ago·verify at source
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