CVE-2025-37752 is an Array-Out-Of-Bounds vulnerability in the Linux network packet scheduler, specifically in the SFQ queuing discipline. An invalid SFQ limit and a series of interactions between SFQ and the TBF Qdisc can lead to a 0x0000 being written approximately 256KB out of bounds at a misaligned offset. If properly exploited, this can enable privilege escalation.
- Spray sfq_slots in kmalloc-64 to prevent an immediate kernel crash when the bug is triggered.
- Prevent a type-confused skb from being dequeued by reconfiguring the TBF Qdisc. Drop TBF rate and add packet overhead before the OOB write occurs.
- Use the 0x0000 written 262636 bytes OOB to corrupt the pipe->files field of a named pipe, free the pipe, cause page-level UAF and get arbitrary R/W in that page.
- Reclaim the freed page with signalfd files and use the page-level R/W primitive to swap file->private_data with file->f_cred.
- Get root by overwriting the process credentials with zeros via signalfd4().bounds at a misaligned offset. If properly exploited, this can enable privilege escalation.