diff options
| 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 /scripts/Makefile.kstack_erase | |
| 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 'scripts/Makefile.kstack_erase')
| -rw-r--r-- | scripts/Makefile.kstack_erase | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/scripts/Makefile.kstack_erase b/scripts/Makefile.kstack_erase new file mode 100644 index 000000000..ee7e4ef7b --- /dev/null +++ b/scripts/Makefile.kstack_erase @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0 + +ifdef CONFIG_GCC_PLUGIN_STACKLEAK +kstack-erase-cflags-y += -fplugin=$(objtree)/scripts/gcc-plugins/stackleak_plugin.so +kstack-erase-cflags-y += -fplugin-arg-stackleak_plugin-track-min-size=$(CONFIG_KSTACK_ERASE_TRACK_MIN_SIZE) +kstack-erase-cflags-y += -fplugin-arg-stackleak_plugin-arch=$(SRCARCH) +kstack-erase-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK_VERBOSE) += -fplugin-arg-stackleak_plugin-verbose +DISABLE_KSTACK_ERASE := -fplugin-arg-stackleak_plugin-disable +endif + +ifdef CONFIG_CC_IS_CLANG +kstack-erase-cflags-y += -fsanitize-coverage=stack-depth +kstack-erase-cflags-y += -fsanitize-coverage-stack-depth-callback-min=$(CONFIG_KSTACK_ERASE_TRACK_MIN_SIZE) +DISABLE_KSTACK_ERASE := -fno-sanitize-coverage=stack-depth +endif + +KSTACK_ERASE_CFLAGS := $(kstack-erase-cflags-y) + +export KSTACK_ERASE_CFLAGS DISABLE_KSTACK_ERASE + +KBUILD_CFLAGS += $(KSTACK_ERASE_CFLAGS) |