From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- drivers/dma/amd/Kconfig | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 drivers/dma/amd/Kconfig (limited to 'drivers/dma/amd/Kconfig') diff --git a/drivers/dma/amd/Kconfig b/drivers/dma/amd/Kconfig new file mode 100644 index 000000000..00d874872 --- /dev/null +++ b/drivers/dma/amd/Kconfig @@ -0,0 +1,42 @@ +# SPDX-License-Identifier: GPL-2.0-only +# + +config AMD_AE4DMA + tristate "AMD AE4DMA Engine" + depends on (X86_64 || COMPILE_TEST) && PCI + depends on AMD_PTDMA + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + help + Enable support for the AMD AE4DMA controller. This controller + provides DMA capabilities to perform high bandwidth memory to + memory and IO copy operations. It performs DMA transfer through + queue-based descriptor management. This DMA controller is intended + to be used with AMD Non-Transparent Bridge devices and not for + general purpose peripheral DMA. + +config AMD_PTDMA + tristate "AMD PassThru DMA Engine" + depends on X86_64 && PCI + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + help + Enable support for the AMD PTDMA controller. This controller + provides DMA capabilities to perform high bandwidth memory to + memory and IO copy operations. It performs DMA transfer through + queue-based descriptor management. This DMA controller is intended + to be used with AMD Non-Transparent Bridge devices and not for + general purpose peripheral DMA. + +config AMD_QDMA + tristate "AMD Queue-based DMA" + depends on HAS_IOMEM + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + select REGMAP_MMIO + help + Enable support for the AMD Queue-based DMA subsystem. The primary + mechanism to transfer data using the QDMA is for the QDMA engine to + operate on instructions (descriptors) provided by the host operating + system. Using the descriptors, the QDMA can move data in either the + Host to Card (H2C) direction or the Card to Host (C2H) direction. -- cgit v1.3.1