null_blk: free zones array on device power-off
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.6.160, 6.12.110, 6.18.52, 7.2.6
- 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: null_blk: free zones array on device power-off null_init_zoned_dev() allocates dev->zones when a zoned device is powered on, but null_del_dev() never frees it on power-off; dev->zones is only freed later in null_free_dev(), when the configfs directory is removed. If the device is powered off and then on again, null_init_zoned_dev() allocates a new array and overwrites the dev->zones pointer, leaking the previous allocation each power cycle. Free dev->zones in null_del_dev() via null_free_zoned_dev() to solve it. And calling null_free_zoned_dev() in null_free_dev() is no longer necessary because every caller already invokes null_del_dev() first: via nullb_group_drop_item() before nullb_device_release(), in the null_add_dev() error path of null_create_dev(), and in null_destroy_dev(). Remove the redundant call. And take &lock around zone_cond_store() in the two store wrappers to serialize dev->zones check-and-deref against its alloc/free, which already run under &lock. The reason there was no problem before is that only nullb_device_release() or null_exit() frees the dev->zones, which guarantees that subsequent users won't access the configfs interface.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From ca4b2a011948fae4e4d31490107db4926385a983 · fixed in 08a31a2cc3d1cea67ccd292d01511cd0a72d4656; From ca4b2a011948fae4e4d31490107db4926385a983 · fixed in 056be41932c95aabdb3c2967d1ef4978f17a0225; From ca4b2a011948fae4e4d31490107db4926385a983 · fixed in b2437d37fcc31fce8a5da1cc1739e284814d2491; From ca4b2a011948fae4e4d31490107db4926385a983 · fixed in 0a3afab87124171022fb3579502fa38ef5b311c9; From ca4b2a011948fae4e4d31490107db4926385a983 · fixed in 2a6357a9b935a34f5508618fee8a7fffbf7722a8
- Linux Linux
4.19
- KernelLinux
From 4.19.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6