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| author | Ali Ahmet Memis <ali@iusegentoo.com> | 2026-08-21 01:45:27 +0000 |
|---|---|---|
| committer | Stafford Horne <shorne@gmail.com> | 2026-08-29 07:32:26 +0100 |
| commit | 78004e9a87f240df03e2f73120d291763c32e0a7 (patch) | |
| tree | 137c22dd795222931b9d2bf2501d37cd766741aa /drivers/gpu/trace | |
| download | linux-stable-78004e9a87f240df03e2f73120d291763c32e0a7.tar.gz linux-stable-78004e9a87f240df03e2f73120d291763c32e0a7.zip | |
openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted
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 <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Diffstat (limited to 'drivers/gpu/trace')
| -rw-r--r-- | drivers/gpu/trace/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/gpu/trace/Makefile | 3 | ||||
| -rw-r--r-- | drivers/gpu/trace/trace_gpu_mem.c | 13 |
3 files changed, 29 insertions, 0 deletions
diff --git a/drivers/gpu/trace/Kconfig b/drivers/gpu/trace/Kconfig new file mode 100644 index 000000000..cd3d19c4a --- /dev/null +++ b/drivers/gpu/trace/Kconfig @@ -0,0 +1,13 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config TRACE_GPU_MEM + bool "Enable GPU memory usage tracepoints" + default n + help + Choose this option to enable tracepoints for tracking + global and per-process GPU memory usage. Intended for + performance profiling and required for Android. + + Tracepoint availability varies by GPU driver. + + If in doubt, say "N". diff --git a/drivers/gpu/trace/Makefile b/drivers/gpu/trace/Makefile new file mode 100644 index 000000000..b70fbdc58 --- /dev/null +++ b/drivers/gpu/trace/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_TRACE_GPU_MEM) += trace_gpu_mem.o diff --git a/drivers/gpu/trace/trace_gpu_mem.c b/drivers/gpu/trace/trace_gpu_mem.c new file mode 100644 index 000000000..01e855897 --- /dev/null +++ b/drivers/gpu/trace/trace_gpu_mem.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GPU memory trace points + * + * Copyright (C) 2020 Google, Inc. + */ + +#include <linux/module.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/gpu_mem.h> + +EXPORT_TRACEPOINT_SYMBOL(gpu_mem_total); |