CVE-2023-53987
Published Dec 24, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: ping: Fix potentail NULL deref for /proc/net/icmp. After commit dbca1596bbb0 ("ping: convert to RCU lookups, get rid of rwlock"), we use RCU for ping sockets, but we should use spinlock for /proc/net/icmp to avoid a potential NULL deref mentioned in the previous patch. Let's go back to using spinlock there. Note we can convert ping sockets to use hlist instead of hlist_nulls because we do not use SLAB_TYPESAFE_BY_RCU for ping sockets.
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References
Frequently Asked Questions
What is CVE-2023-53987? +
In the Linux kernel, the following vulnerability has been resolved:
ping: Fix potentail NULL deref for /proc/net/icmp.
After commit dbca1596bbb0 ("ping: convert to RCU lookups, get rid
of rwlock"), we use RCU for ping sockets, but we should use spinlock
for /proc/net/icmp to avoid a potential NULL deref mentioned in
the previous patch.
Let's go back to using spinlock there.
Note we can convert ping sockets to use hlist instead of hlist_nulls
because we do not use SLAB_TYPESAFE_BY_RCU for ping sockets.
How do I check if I'm vulnerable to CVE-2023-53987? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.