bpf: Take mmap_lock in zap_pages()
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 7.1.5
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From 317460317a02a1af512697e6e964298dedd8a163 · fixed in 36b1d997866f6083d33934983aa2ce0a184ed642; From 317460317a02a1af512697e6e964298dedd8a163 · fixed in 80b89d0226a05e8b67969de99c31b51fcd54f76a
- Linux Linux
6.9
- KernelLinux
From 6.9.0 · fixed in 7.1.5