CVE-2026-90348 wifi: ath10k: snoc: use memcpy_fromio() for MSA ramdump
A kernel crash occurs in the ath10k WiFi driver when collecting firmware dumps on specific hardware due to unaligned memory access, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90348?
CVE-2026-90348 is a denial of service vulnerability in Linux, published on 17 Sep 2026. 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: ath10k: snoc: use memcpy_fromio() for MSA ramdump
On WCN3990/SNOC the MSA region is mapped with devm_memremap(MEMREMAP_WT). On arm64 such a mapping is not Normal-cacheable, so unaligned accesses to it are not permitted. ath10k_msa_dump_memory() copies the region with a plain memcpy(), whose optimized __pi_memcpy_generic implementation issues wide/unaligned loads. This triggers an alignment fault (FSC=0x21) Oops in ath10k_snoc_fw_crashed_dump() while collecting the devcoredump:
Unable to handle kernel paging request ... FSC=0x21: alignment fault pc : __pi_memcpy_generic lr : ath10k_snoc_fw_crashed_dump [ath10k_snoc]
The Oops both leaves the firmware RAM dump buffer zeroed (no dump is captured) and crashes the kernel, which in turn breaks modem SSR recovery.
Use memcpy_fromio(), which only performs accesses that are valid for such a device-memory mapping. The generic memcpy_fromio() implementation aligns the source before issuing word-sized reads and stores the destination with put_unaligned(), so it is also safe for the coherent DMA allocation used on the non-reserved-memory path. ath11k and ath12k use the same pattern when copying target memory into crash dumps, so call it unconditionally here too. The MEMREMAP_WT pointer is a plain void *, so an explicit __iomem cast is needed; use __force to keep sparse happy.
Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.3.3.7.c5-00107-QCAHLSWMTPL-1
Which versions are affected by CVE-2026-90348?
How do I fix CVE-2026-90348?
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-2026-90348 being exploited?
There is no known exploitation of CVE-2026-90348 in the wild and no public exploit code.
Sources
Also known as AZL-102615, BELL-CVE-2026-90348, DEBIAN-CVE-2026-90348, GHSA-72gw-r7x5-6v8v, UBUNTU-CVE-2026-90348.