CVE-2026-53374 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: zero-initialize GART table on allocation
GART TLB is flushed after unmapping but not after mapping. Since amdgpu_bo_create_kernel() does not zero-initialize the buffer, when a single PTE is written the TLB may speculatively load other uninitialized entries from the same cacheline. Those garbage entries can appear valid, and a subsequent write to another PTE in the same cacheline may cause the GPU to use a stale garbage PTE from the TLB.
Fix this by calling memset_io() to zero-initialize the GART table with gart_pte_flags immediately after allocation.
Using AMDGPU_GEM_CREATE_VRAM_CLEARED, SDMA-based clear will not work since SDMA needs GART to be initialized to work.
(cherry picked from commit d9af8263b82b6eaa60c5718e0c6631c5037e4b24)
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Analysis
by VulDB Data Team • 07/19/2026
The vulnerability in the Linux kernel's AMDGPU driver represents a critical memory management flaw that affects the graphics address translation lookaside buffer (TLB) behavior during GPU memory allocation operations. This issue specifically impacts the drm/amdgpu subsystem where the GART (Graphics Address Translation Table) table handling contains a fundamental initialization defect. The problem manifests when creating kernel buffers through the amdgpu_bo_create_kernel() function, which fails to properly zero-initialize buffer memory before use, creating potential security implications in GPU memory management.
The technical flaw stems from the improper handling of PTE (Page Table Entry) initialization within the GART table allocation process. When a buffer is allocated without zeroing the entire table structure, subsequent memory operations can result in speculative loading of uninitialized data from the same cacheline. This occurs because the GPU's TLB flush mechanism only occurs during unmapping operations but not during mapping operations, leaving stale entries in the translation cache. The lack of proper initialization means that garbage values from previously allocated or freed memory regions can persist in the PTE entries, appearing as valid translations to the GPU hardware.
This vulnerability creates a significant operational impact by enabling potential information disclosure and privilege escalation scenarios within the graphics subsystem. An attacker could potentially manipulate GPU memory operations to access or corrupt data through stale TLB entries that contain remnants of previously used memory regions. The flaw particularly affects systems utilizing AMDGPU drivers where kernel buffer creation is common, potentially allowing malicious processes to exploit the uninitialized memory contents for unauthorized data access or system compromise.
The proposed fix implements a comprehensive memory initialization strategy by incorporating memset_io() calls immediately after GART table allocation with proper gart_pte_flags handling. This approach ensures that all PTE entries are properly zeroed before any mapping operations occur, eliminating the possibility of speculative loading from uninitialized cacheline portions. The solution specifically addresses the constraint where AMDGPU_GEM_CREATE_VRAM_CLEARED cannot be used due to SDMA-based clearing mechanisms requiring GART initialization to function properly, making this fix a necessary prerequisite for proper memory management.
This vulnerability aligns with CWE-754: Improper Check for Unusual or Exceptional Conditions and relates to ATT&CK technique T1068: Exploitation for Privilege Escalation through memory corruption vulnerabilities. The fix demonstrates proper defensive programming practices by ensuring memory initialization before use, which is essential for maintaining the integrity of GPU memory management operations. The implementation pattern follows established security principles that prevent information leakage through uninitialized memory access patterns, particularly relevant in graphics processing units where memory translation cache behaviors can create subtle but critical security implications.