CVEvulnerability
CVE-2026-43169
5.5 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-05-06
- Last modified
- 2026-06-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 ([email protected])
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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
Affected configurations
• linux linux kernel (>= 6.7 < 6.12.75)
• linux linux kernel (>= 6.13 < 6.18.16)
• linux linux kernel (>= 6.19 < 6.19.6)
References
- https://git.kernel.org/stable/c/5488a29596cdba93a60a79398dc9b69d5bdadf92 Patch
- https://git.kernel.org/stable/c/6236c1cd9fdf433d39ed28b2491ccdfe7ae95061 Patch
- https://git.kernel.org/stable/c/d764b8dd420098a4d253b8a5b27568c897edb2cf Patch
- https://git.kernel.org/stable/c/ecb32c60d8cbed2ee9ce9f343b6aa2f32babc727 Patch