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 --- samples/trace_events/Makefile | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 samples/trace_events/Makefile (limited to 'samples/trace_events/Makefile') diff --git a/samples/trace_events/Makefile b/samples/trace_events/Makefile new file mode 100644 index 000000000..b3808bb4c --- /dev/null +++ b/samples/trace_events/Makefile @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0-only +# builds the trace events example kernel modules; +# then to use one (as root): insmod + +# If you include a trace header outside of include/trace/events +# then the file that does the #define CREATE_TRACE_POINTS must +# have that tracer file in its main search path. This is because +# define_trace.h will include it, and must be able to find it from +# the include/trace directory. +# +# Here trace-events-sample.c does the CREATE_TRACE_POINTS. +# +CFLAGS_trace-events-sample.o := -I$(src) +CFLAGS_trace_custom_sched.o := -I$(src) + +obj-$(CONFIG_SAMPLE_TRACE_EVENTS) += trace-events-sample.o +obj-$(CONFIG_SAMPLE_TRACE_CUSTOM_EVENTS) += trace_custom_sched.o -- cgit v1.3.1