Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

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

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

kernel-devel-7.2.7-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 193 more

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