CVE-2024-49937 wifi: cfg80211: Set correct chandef when starting CAC
A null pointer dereference in the Linux kernel WiFi subsystem can cause a system crash when starting Channel Availability Check in non-AP modes.
- 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-2024-49937?
CVE-2024-49937 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 2024. 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:
wifi: cfg80211: Set correct chandef when starting CAC
When starting CAC in a mode other than AP mode, it return a "WARNING: CPU: 0 PID: 63 at cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]" caused by the chandef.chan being null at the end of CAC.
Solution: Ensure the channel definition is set for the different modes when starting CAC to avoid getting a NULL 'chan' at the end of CAC.
Call Trace: ? show_regs.part.0+0x14/0x16 ? __warn+0x67/0xc0 ? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211] ? report_bug+0xa7/0x130 ? exc_overflow+0x30/0x30 ? handle_bug+0x27/0x50 ? exc_invalid_op+0x18/0x60 ? handle_exception+0xf6/0xf6 ? exc_overflow+0x30/0x30 ? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211] ? exc_overflow+0x30/0x30 ? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211] ? regulatory_propagate_dfs_state.cold+0x1b/0x4c [cfg80211] ? cfg80211_propagate_cac_done_wk+0x1a/0x30 [cfg80211] ? process_one_work+0x165/0x280 ? worker_thread+0x120/0x3f0 ? kthread+0xc2/0xf0 ? process_one_work+0x280/0x280 ? kthread_complete_and_exit+0x20/0x20 ? ret_from_fork+0x19/0x24
[shorten subject, remove OCB, reorder cases to match previous list]
Which versions are affected by CVE-2024-49937?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-49937?
Apply the vendor's patch.
Is CVE-2024-49937 being exploited?
There is no known exploitation of CVE-2024-49937 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-53045, BELL-CVE-2024-49937, DEBIAN-CVE-2024-49937, GHSA-64qp-9xf4-2pch, ROOT-OS-DEBIAN-11-CVE-2024-49937, ROOT-OS-UBUNTU-2204-CVE-2024-49937 and 1 more.