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 --- scripts/dtc/include-prefixes/arc | 1 + scripts/dtc/include-prefixes/arm | 1 + scripts/dtc/include-prefixes/arm64 | 1 + scripts/dtc/include-prefixes/dt-bindings | 1 + scripts/dtc/include-prefixes/microblaze | 1 + scripts/dtc/include-prefixes/mips | 1 + scripts/dtc/include-prefixes/nios2 | 1 + scripts/dtc/include-prefixes/openrisc | 1 + scripts/dtc/include-prefixes/powerpc | 1 + scripts/dtc/include-prefixes/riscv | 1 + scripts/dtc/include-prefixes/sh | 1 + scripts/dtc/include-prefixes/xtensa | 1 + 12 files changed, 12 insertions(+) create mode 120000 scripts/dtc/include-prefixes/arc create mode 120000 scripts/dtc/include-prefixes/arm create mode 120000 scripts/dtc/include-prefixes/arm64 create mode 120000 scripts/dtc/include-prefixes/dt-bindings create mode 120000 scripts/dtc/include-prefixes/microblaze create mode 120000 scripts/dtc/include-prefixes/mips create mode 120000 scripts/dtc/include-prefixes/nios2 create mode 120000 scripts/dtc/include-prefixes/openrisc create mode 120000 scripts/dtc/include-prefixes/powerpc create mode 120000 scripts/dtc/include-prefixes/riscv create mode 120000 scripts/dtc/include-prefixes/sh create mode 120000 scripts/dtc/include-prefixes/xtensa (limited to 'scripts/dtc/include-prefixes') diff --git a/scripts/dtc/include-prefixes/arc b/scripts/dtc/include-prefixes/arc new file mode 120000 index 000000000..5d21b5a69 --- /dev/null +++ b/scripts/dtc/include-prefixes/arc @@ -0,0 +1 @@ +../../../arch/arc/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/arm b/scripts/dtc/include-prefixes/arm new file mode 120000 index 000000000..eb14d4515 --- /dev/null +++ b/scripts/dtc/include-prefixes/arm @@ -0,0 +1 @@ +../../../arch/arm/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/arm64 b/scripts/dtc/include-prefixes/arm64 new file mode 120000 index 000000000..275c42c21 --- /dev/null +++ b/scripts/dtc/include-prefixes/arm64 @@ -0,0 +1 @@ +../../../arch/arm64/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/dt-bindings b/scripts/dtc/include-prefixes/dt-bindings new file mode 120000 index 000000000..04fdbb3af --- /dev/null +++ b/scripts/dtc/include-prefixes/dt-bindings @@ -0,0 +1 @@ +../../../include/dt-bindings \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/microblaze b/scripts/dtc/include-prefixes/microblaze new file mode 120000 index 000000000..d9830330a --- /dev/null +++ b/scripts/dtc/include-prefixes/microblaze @@ -0,0 +1 @@ +../../../arch/microblaze/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/mips b/scripts/dtc/include-prefixes/mips new file mode 120000 index 000000000..ae8d4948d --- /dev/null +++ b/scripts/dtc/include-prefixes/mips @@ -0,0 +1 @@ +../../../arch/mips/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/nios2 b/scripts/dtc/include-prefixes/nios2 new file mode 120000 index 000000000..51772336d --- /dev/null +++ b/scripts/dtc/include-prefixes/nios2 @@ -0,0 +1 @@ +../../../arch/nios2/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/openrisc b/scripts/dtc/include-prefixes/openrisc new file mode 120000 index 000000000..71c3bc75c --- /dev/null +++ b/scripts/dtc/include-prefixes/openrisc @@ -0,0 +1 @@ +../../../arch/openrisc/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/powerpc b/scripts/dtc/include-prefixes/powerpc new file mode 120000 index 000000000..7cd6ec16e --- /dev/null +++ b/scripts/dtc/include-prefixes/powerpc @@ -0,0 +1 @@ +../../../arch/powerpc/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/riscv b/scripts/dtc/include-prefixes/riscv new file mode 120000 index 000000000..202509418 --- /dev/null +++ b/scripts/dtc/include-prefixes/riscv @@ -0,0 +1 @@ +../../../arch/riscv/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/sh b/scripts/dtc/include-prefixes/sh new file mode 120000 index 000000000..67d37808c --- /dev/null +++ b/scripts/dtc/include-prefixes/sh @@ -0,0 +1 @@ +../../../arch/sh/boot/dts \ No newline at end of file diff --git a/scripts/dtc/include-prefixes/xtensa b/scripts/dtc/include-prefixes/xtensa new file mode 120000 index 000000000..d1eaf6ec7 --- /dev/null +++ b/scripts/dtc/include-prefixes/xtensa @@ -0,0 +1 @@ +../../../arch/xtensa/boot/dts \ No newline at end of file -- cgit v1.3.1