In the Linux kernel, the following vulnerability has been resolved:
drm/buddy: Prevent BUG_ON by validating rounded allocation
When DRM_BUDDY_CONTIGUOUS_ALLOCATION is set, the requested size is
rounded up to the next power-of-two via roundup_pow_of_two().
Similarly, for non-contiguous allocations with large min_block_size,
the size is aligned up via round_up(). Both operations can produce a
rounded size that exceeds mm->size, which later triggers
BUG_ON(order > mm->max_order).
Example scenarios:
- 9G CONTIGUOUS allocation on 10G VRAM memory:
roundup_pow_of_two(9G) = 16G > 10G
- 9G allocation with 8G min_block_size on 10G VRAM memory:
round_up(9G, 8G) = 16G > 10G
Fix this by checking the rounded size against mm->size. For
non-contiguous or range allocations where size > mm->size is invalid,
return -EINVAL immediately. For contiguous allocations without range
restrictions, allow the request to fall through to the existing
__alloc_contig_try_harder() fallback.
This ensures invalid user input returns an error or uses the fallback
path instead of hitting BUG_ON.
v2: (Matt A)
- Add Fixes, Cc stable, and Closes tags for context
drm/buddy: Prevent BUG_ON by validating rounded allocation
When DRM_BUDDY_CONTIGUOUS_ALLOCATION is set, the requested size is
rounded up to the next power-of-two via roundup_pow_of_two().
Similarly, for non-contiguous allocations with large min_block_size,
the size is aligned up via round_up(). Both operations can produce a
rounded size that exceeds mm->size, which later triggers
BUG_ON(order > mm->max_order).
Example scenarios:
- 9G CONTIGUOUS allocation on 10G VRAM memory:
roundup_pow_of_two(9G) = 16G > 10G
- 9G allocation with 8G min_block_size on 10G VRAM memory:
round_up(9G, 8G) = 16G > 10G
Fix this by checking the rounded size against mm->size. For
non-contiguous or range allocations where size > mm->size is invalid,
return -EINVAL immediately. For contiguous allocations without range
restrictions, allow the request to fall through to the existing
__alloc_contig_try_harder() fallback.
This ensures invalid user input returns an error or uses the fallback
path instead of hitting BUG_ON.
v2: (Matt A)
- Add Fixes, Cc stable, and Closes tags for context
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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Fixes
Solution
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Workaround
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References
History
Wed, 06 May 2026 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: drm/buddy: Prevent BUG_ON by validating rounded allocation When DRM_BUDDY_CONTIGUOUS_ALLOCATION is set, the requested size is rounded up to the next power-of-two via roundup_pow_of_two(). Similarly, for non-contiguous allocations with large min_block_size, the size is aligned up via round_up(). Both operations can produce a rounded size that exceeds mm->size, which later triggers BUG_ON(order > mm->max_order). Example scenarios: - 9G CONTIGUOUS allocation on 10G VRAM memory: roundup_pow_of_two(9G) = 16G > 10G - 9G allocation with 8G min_block_size on 10G VRAM memory: round_up(9G, 8G) = 16G > 10G Fix this by checking the rounded size against mm->size. For non-contiguous or range allocations where size > mm->size is invalid, return -EINVAL immediately. For contiguous allocations without range restrictions, allow the request to fall through to the existing __alloc_contig_try_harder() fallback. This ensures invalid user input returns an error or uses the fallback path instead of hitting BUG_ON. v2: (Matt A) - Add Fixes, Cc stable, and Closes tags for context | |
| Title | drm/buddy: Prevent BUG_ON by validating rounded allocation | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-06T11:27:45.356Z
Reserved: 2026-05-01T14:12:55.990Z
Link: CVE-2026-43169
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2026-05-06T12:16:35.197
Modified: 2026-05-06T13:07:51.607
Link: CVE-2026-43169
Redhat
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OpenCVE Enrichment
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Weaknesses
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