CVE-2025-38646 wifi: rtw89: avoid NULL dereference when RX problematic packet on unsupported 6 GHz band
A rare race condition in the rtw89 WiFi driver causes a kernel crash when processing specific packets on unsupported 6 GHz bands.
- 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-2025-38646?
CVE-2025-38646 is a medium-severity vulnerability in Linux kernel, published on 22 Aug 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:
wifi: rtw89: avoid NULL dereference when RX problematic packet on unsupported 6 GHz band
With a quite rare chance, RX report might be problematic to make SW think a packet is received on 6 GHz band even if the chip does not support 6 GHz band actually. Since SW won't initialize stuffs for unsupported bands, NULL dereference will happen then in the sequence, rtw89_vif_rx_stats_iter() -> rtw89_core_cancel_6ghz_probe_tx(). So, add a check to avoid it.
The following is a crash log for this case.
BUG: kernel NULL pointer dereference, address: 0000000000000032 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 1907 Comm: irq/131-rtw89_p Tainted: G U 6.6.56-05896-g89f5fb0eb30b #1 (HASH:1400 4) Hardware name: Google Telith/Telith, BIOS Google_Telith.15217.747.0 11/12/2024 RIP: 0010:rtw89_vif_rx_stats_iter+0xd2/0x310 [rtw89_core] Code: 4c 89 7d c8 48 89 55 c0 49 8d 44 24 02 48 89 45 b8 45 31 ff eb 11 41 c6 45 3a 01 41 b7 01 4d 8b 6d 00 4d 39 f5 74 42 8b 43 10 <41> 33 45 32 0f b7 4b 14 66 41 33 4d 36 0f b7 c9 09 c1 74 d8 4d 85 RSP: 0018:ffff9f3080138ca0 EFLAGS: 00010246 RAX: 00000000b8bf5770 RBX: ffff91b5e8c639c0 RCX: 0000000000000011 RDX: ffff91b582de1be8 RSI: 0000000000000000 RDI: ffff91b5e8c639e6 RBP: ffff9f3080138d00 R08: 0000000000000000 R09: 0000000000000000 R10: ffff91b59de70000 R11: ffffffffc069be50 R12: ffff91b5e8c639e4 R13: 0000000000000000 R14: ffff91b5828020b8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff91b8efa40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000032 CR3: 00000002bf838000 CR4: 0000000000750ee0 PKRU: 55555554 Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_rtw89_vif_rx_stats_iter+0x10/0x10 [rtw89_core (HASH:1400 5)] ? rtw89_vif_rx_stats_iter+0xd2/0x310 [rtw89_core (HASH:1400 5)] __iterate_interfaces+0x59/0x110 [mac80211 (HASH:1400 6)] ? __pfx_rtw89_vif_rx_stats_iter+0x10/0x10 [rtw89_core (HASH:1400 5)] ? __pfx_rtw89_vif_rx_stats_iter+0x10/0x10 [rtw89_core (HASH:1400 5)] ieee80211_iterate_active_interfaces_atomic+0x36/0x50 [mac80211 (HASH:1400 6)] rtw89_core_rx_to_mac80211+0xfd/0x1b0 [rtw89_core (HASH:1400 5)] rtw89_core_rx+0x43a/0x980 [rtw89_core (HASH:1400 5)]
Weakness: CWE-476
Which versions are affected by CVE-2025-38646?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-38646?
Apply the vendor's patch.
Is CVE-2025-38646 being exploited?
There is no known exploitation of CVE-2025-38646 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-66650, BELL-CVE-2025-38646, DEBIAN-CVE-2025-38646, GHSA-5vg6-qhc8-fjr6, ROOT-OS-DEBIAN-13-CVE-2025-38646, ROOT-OS-UBUNTU-2404-CVE-2025-38646 and 1 more.