pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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
- 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
Summary
In the Linux kernel, the following vulnerability has been resolved: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() pwrseq_debugfs_seq_next() declares 'next' with __free(put_device), which causes put_device() to be called on the returned pointer when the variable goes out of scope. This results in a use-after-free since the seq_file framework receives a pointer whose reference has already been dropped. Simply removing __free(put_device) would fix the UAF but would leak the reference acquired by bus_find_next_device(), as stop() only calls up_read(&pwrseq_sem) and never releases the device reference. Fix this by making the reference counting consistent across all seq_file callbacks, matching the standard pattern used by PCI and SCSI: • start(): use get_device() so it returns a referenced pointer. • next(): explicitly put_device(curr) to release the previous device's reference (no NULL check needed - the seq_file framework only calls next() while the previous return was non-NULL). • stop(): put_device(data) to release the last iterated device's reference, with a NULL guard since stop() may be called with NULL when start() returned NULL or next() reached end-of-sequence.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
6.11