CVE-2024-38616 wifi: carl9170: re-fix fortified-memset warning
A fortified-memset warning in the carl9170 Wi-Fi driver can lead to a build failure or potential memory corruption issues, requiring a kernel patch.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-38616?
CVE-2024-38616 is a high-severity denial of service vulnerability in Linux kernel, published on 19 Jun 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
wifi: carl9170: re-fix fortified-memset warning
The carl9170_tx_release() function sometimes triggers a fortified-memset warning in my randconfig builds:
In file included from include/linux/string.h:254, from drivers/net/wireless/ath/carl9170/tx.c:40: In function 'fortify_memset_chk', inlined from 'carl9170_tx_release' at drivers/net/wireless/ath/carl9170/tx.c:283:2, inlined from 'kref_put' at include/linux/kref.h:65:3, inlined from 'carl9170_tx_put_skb' at drivers/net/wireless/ath/carl9170/tx.c:342:9: include/linux/fortify-string.h:493:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 493 | __write_overflow_field(p_size_field, size);
Kees previously tried to avoid this by using memset_after(), but it seems this does not fully address the problem. I noticed that the memset_after() here is done on a different part of the union (status) than the original cast was from (rate_driver_data), which may confuse the compiler.
Unfortunately, the memset_after() trick does not work on driver_rates[] because that is part of an anonymous struct, and I could not get struct_group() to do this either. Using two separate memset() calls on the two members does address the warning though.
Weakness: CWE-400
Which versions are affected by CVE-2024-38616?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-38616?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-38616 being exploited?
There is no known exploitation of CVE-2024-38616 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-38616, DEBIAN-CVE-2024-38616, GHSA-3wf5-cgv3-f3xm, UBUNTU-CVE-2024-38616.