CVE-2023-53210 md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid()
A race condition in the Linux kernel's RAID5 cache can cause a null pointer dereference, leading to a system crash.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-53210?
CVE-2023-53210 is a medium-severity vulnerability in Linux kernel, published on 15 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid()
r5l_flush_stripe_to_raid() will check if the list 'flushing_ios' is empty, and then submit 'flush_bio', however, r5l_log_flush_endio() is clearing the list first and then clear the bio, which will cause null-ptr-deref:
T1: submit flush io raid5d handle_active_stripes r5l_flush_stripe_to_raid // list is empty // add 'io_end_ios' to the list bio_init submit_bio // io1
T2: io1 is done r5l_log_flush_endio list_splice_tail_init // clear the list T3: submit new flush io ... r5l_flush_stripe_to_raid // list is empty // add 'io_end_ios' to the list bio_init bio_uninit // clear bio->bi_blkg submit_bio // null-ptr-deref
Fix this problem by clearing bio before clearing the list in r5l_log_flush_endio().
Weakness: CWE-476
Which versions are affected by CVE-2023-53210?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53210?
Apply the vendor's patch.
Is CVE-2023-53210 being exploited?
There is no known exploitation of CVE-2023-53210 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53210, DEBIAN-CVE-2023-53210, GHSA-g3v4-29h4-3gxq, UBUNTU-CVE-2023-53210.