CVE-2026-63878: drm/amdgpu: check num_entries in GEM_OP GET_MAPPING_INFO

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-19 · updated 2026-10-30

Description

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)

Affected products

Linux kernel: from 6.18 before 6.18.35; from 6.19 before 7.0.12; 7.1-rc1, 7.1-rc2, 7.1-rc3, 7.1-rc4, 7.1-rc5 — fixed in 6.18.35, 7.0.12
Linux kernel: 6.18 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 6.18.35, 7.0.12; Linux kernel 7.1. Check the vendor advisory for mitigations.

References

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