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 /arch/x86/Makefile_32.cpu | |
| 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 'arch/x86/Makefile_32.cpu')
| -rw-r--r-- | arch/x86/Makefile_32.cpu | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu new file mode 100644 index 000000000..c5aa169b5 --- /dev/null +++ b/arch/x86/Makefile_32.cpu @@ -0,0 +1,36 @@ +# SPDX-License-Identifier: GPL-2.0 +# CPU tuning section - shared with UML. +# Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML. + +tune = $(call cc-option,-mtune=$(1),$(2)) + +ifdef CONFIG_CC_IS_CLANG +align := -falign-functions=0 $(call cc-option,-falign-jumps=0) $(call cc-option,-falign-loops=0) +else +align := -falign-functions=0 -falign-jumps=0 -falign-loops=0 +endif + +cflags-$(CONFIG_M586TSC) += -march=i586 +cflags-$(CONFIG_M586MMX) += -march=pentium-mmx +cflags-$(CONFIG_M686) += -march=i686 +cflags-$(CONFIG_MPENTIUMII) += -march=i686 $(call tune,pentium2) +cflags-$(CONFIG_MPENTIUMIII) += -march=i686 $(call tune,pentium3) +cflags-$(CONFIG_MPENTIUMM) += -march=i686 $(call tune,pentium3) +cflags-$(CONFIG_MPENTIUM4) += -march=i686 $(call tune,pentium4) +cflags-$(CONFIG_MK6) += -march=k6 +# Please note, that patches that add -march=athlon-xp and friends are pointless. +# They make zero difference whatsosever to performance at this time. +cflags-$(CONFIG_MK7) += -march=athlon +cflags-$(CONFIG_MCRUSOE) += -march=i686 $(align) +cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) $(align) +cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) $(align) +cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686) +cflags-$(CONFIG_MVIAC7) += -march=i686 +cflags-$(CONFIG_MATOM) += -march=atom + +# Geode GX1 support +cflags-$(CONFIG_MGEODEGX1) += -march=pentium-mmx +cflags-$(CONFIG_MGEODE_LX) += $(call cc-option,-march=geode,-march=pentium-mmx) +# add at the end to overwrite eventual tuning options from earlier +# cpu entries +cflags-$(CONFIG_X86_GENERIC) += $(call tune,generic,$(call tune,i686)) |