CVE-2025-38646: linux kernel Null Dereference — Fix

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)]

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.4 — 6.6.102
linux	linux_kernel	6.7 — 6.12.42
linux	linux_kernel	6.13 — 6.15.10
linux	linux_kernel	6.16 — 6.16.1

References

Advisories & Patches

https://git.kernel.org/stable/c/4b525630729082f026e7030eafccf89e3add7eae https://git.kernel.org/stable/c/77a7a48f87d673a68664bebf044214821decbfda https://git.kernel.org/stable/c/7e04f01bb94fe61c73cc59f0495c3b6c16a83231 https://git.kernel.org/stable/c/892b29eab44b1803d2cad8e50f1bc2144ef478cb https://git.kernel.org/stable/c/f3527ac15a00916e68ecb495b74dbe6a6c62a06f

Frequently Asked Questions

What is CVE-2025-38646? +

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)] It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2025-38646? +

CVE-2025-38646 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-38646? +

CVE-2025-38646 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-38646? +

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.

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CVE-2025-38646