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/gpu/amdgpu/ras.rst | 62 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 Documentation/gpu/amdgpu/ras.rst (limited to 'Documentation/gpu/amdgpu/ras.rst') diff --git a/Documentation/gpu/amdgpu/ras.rst b/Documentation/gpu/amdgpu/ras.rst new file mode 100644 index 000000000..047f76e39 --- /dev/null +++ b/Documentation/gpu/amdgpu/ras.rst @@ -0,0 +1,62 @@ +==================== + AMDGPU RAS Support +==================== + +The AMDGPU RAS interfaces are exposed via sysfs (for informational queries) and +debugfs (for error injection). + +RAS debugfs/sysfs Control and Error Injection Interfaces +======================================================== + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c + :doc: AMDGPU RAS debugfs control interface + +RAS Reboot Behavior for Unrecoverable Errors +============================================ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c + :doc: AMDGPU RAS Reboot Behavior for Unrecoverable Errors + +RAS Error Count sysfs Interface +=============================== + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c + :doc: AMDGPU RAS sysfs Error Count Interface + +RAS EEPROM debugfs Interface +============================ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c + :doc: AMDGPU RAS debugfs EEPROM table reset interface + +RAS VRAM Bad Pages sysfs Interface +================================== + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c + :doc: AMDGPU RAS sysfs gpu_vram_bad_pages Interface + +Sample Code +=========== +Sample code for testing error injection can be found here: +https://cgit.freedesktop.org/mesa/drm/tree/tests/amdgpu/ras_tests.c + +This is part of the libdrm amdgpu unit tests which cover several areas of the GPU. +There are four sets of tests: + +RAS Basic Test + +The test verifies the RAS feature enabled status and makes sure the necessary sysfs and debugfs files +are present. + +RAS Query Test + +This test checks the RAS availability and enablement status for each supported IP block as well as +the error counts. + +RAS Inject Test + +This test injects errors for each IP. + +RAS Disable Test + +This test tests disabling of RAS features for each IP block. -- cgit v1.3.1