Bug 2516793 (CVE-2026-74354) - CVE-2026-74354 kernel: bpf: Take mmap_lock in zap_pages()
Summary: CVE-2026-74354 kernel: bpf: Take mmap_lock in zap_pages()
Keywords:
Status: NEW
Alias: CVE-2026-74354
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 06:33 UTC by OSIDB Bzimport
Modified: 2026-08-19 09:03 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2026-08-15 06:33:45 UTC
In the Linux kernel, the following vulnerability has been resolved:

bpf: Take mmap_lock in zap_pages()

zap_vma_range() requires the owning mm's mmap_lock to be held.

Taking mmap_read_lock under arena->lock would AB-BA against
arena_vm_close() and arena_map_mmap(), both of which run with
mmap_write_lock held and then acquire arena->lock. Instead drop
arena->lock, mmget_not_zero() the vma's mm, take mmap_read_lock, and
re-resolve the vma via find_vma() since it may have been unmapped or
replaced while waiting.

Track processed vmls with a per-call generation in vml->zap_gen and
serialize zap_pages() callers with a new arena->zap_mutex so
concurrent callers on different uaddr ranges do not mark each other's
vmls processed before the zap is done.


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