high CVSS 7.8

CVE-2024-38562·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: wifi: nl80211: Avoid address calculations via out of bounds array indexing Before request->channels[] can be used, request->n_channels must be set. Additionally, address calculations for memory after the "channels" array need to be calculated from the allocation base ("request") rather than via the first "out of bounds" index of "channels", otherwise run-time bounds checking will throw a warning.

Severity
high
Software
Kernel
Fixed in
6.9.3
Published
2024-06-19

Affected versions

From: 6.9

Until: 6.9.3

Fixed in: 6.9.3

How to fix this CVE

Update your Linux kernel to version 6.9.3 or later to resolve this memory safety issue in the nl80211 wireless subsystem. The vulnerability stems from improper address calculations when accessing the channels array without proper bounds checking. Apply the kernel update through your distribution's package manager and reboot the system to activate the patched kernel.

sudo dnf check-update kernel && sudo dnf update kernel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Check current kernel version: uname -r — confirm it is NOT between 6.9 and 6.9.2
  2. Verify nl80211 module is loaded: lsmod | grep cfg80211 — determines if wireless driver is active
  3. Review kernel messages for bounds check warnings: sudo dmesg | grep -i 'out of bounds' — look for sanitizer warnings related to array access
  4. Confirm patch application: grep -r 'request->n_channels' /lib/modules/$(uname -r)/kernel/net/wireless/ 2>/dev/null || echo 'Patched version installed'

FAQ

What is CVE-2024-38562?

This vulnerability in Linux kernel's nl80211 subsystem allows improper memory address calculations when accessing wireless channel configuration arrays, potentially causing kernel warnings or undefined behavior if the channels count is not validated before array access.

Is CVE-2024-38562 being actively exploited?

No, this vulnerability is not currently being actively exploited according to CISA KEV data, and no public exploit code is available.

What versions of Kernel are affected by CVE-2024-38562?

Linux kernel versions 6.9 through 6.9.2 are affected. Version 6.9.3 and later contain the fix.

How do I check if my server is vulnerable to CVE-2024-38562?

Run `uname -r` and check if the output shows a kernel version between 6.9 and 6.9.2 inclusive. If so, your system is vulnerable.

Does Defensia detect CVE-2024-38562?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2024-38562 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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CVE-2026-43501CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: rpl: reserve mac_len headroom when recompressed SRH grows ipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps the next segment into ipv6_hdr->daddr, recompresses, then pulls the old header and pushes the new one plus the IPv6 header back. The recompressed header can be larger than the received one when the swap reduces the common-prefix length the segments share with daddr (CmprI=0, CmprE>0, seg[0][0] != daddr[0] gives the maximum +8 bytes). pskb_expand_head() was gated on segments_left == 0, so on earlier segments the push consumed unchecked headroom. Once skb_push() leaves fewer than skb->mac_len bytes in front of data, skb_mac_header_rebuild()'s call to: skb_set_mac_header(skb, -skb->mac_len); will store (data - head) - mac_len into the u16 mac_header field, which wraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB past skb->head. A single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two segment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one pass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv. Fix this by expanding the head whenever the remaining room is less than the push size plus mac_len, and request that much extra so the rebuilt MAC header fits afterwards.
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References

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