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 --- Documentation/driver-api/dmaengine/index.rst | 48 ++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 Documentation/driver-api/dmaengine/index.rst (limited to 'Documentation/driver-api/dmaengine/index.rst') diff --git a/Documentation/driver-api/dmaengine/index.rst b/Documentation/driver-api/dmaengine/index.rst new file mode 100644 index 000000000..e74677c66 --- /dev/null +++ b/Documentation/driver-api/dmaengine/index.rst @@ -0,0 +1,48 @@ +======================= +DMAEngine documentation +======================= + +DMAEngine documentation provides documents for various aspects of DMAEngine +framework. + +DMAEngine development documentation +----------------------------------- + +This book helps with DMAengine internal APIs and guide for DMAEngine device +driver writers. + +.. toctree:: + :maxdepth: 1 + + provider + +DMAEngine client documentation +------------------------------ + +This book is a guide to device driver writers on how to use the Slave-DMA +API of the DMAEngine. This is applicable only for slave DMA usage only. + +.. toctree:: + :maxdepth: 1 + + client + +DMA Test documentation +---------------------- + +This book introduces how to test DMA drivers using dmatest module. + +.. toctree:: + :maxdepth: 1 + + dmatest + +PXA DMA documentation +---------------------- + +This book adds some notes about PXA DMA + +.. toctree:: + :maxdepth: 1 + + pxa_dma -- cgit v1.3.1