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/check-function-names.sh | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100755 scripts/check-function-names.sh (limited to 'scripts/check-function-names.sh') diff --git a/scripts/check-function-names.sh b/scripts/check-function-names.sh new file mode 100755 index 000000000..08071133e --- /dev/null +++ b/scripts/check-function-names.sh @@ -0,0 +1,25 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# Certain function names are disallowed due to section name ambiguities +# introduced by -ffunction-sections. +# +# See the comment above TEXT_MAIN in include/asm-generic/vmlinux.lds.h. + +objfile="$1" + +if [ ! -f "$objfile" ]; then + echo "usage: $0 " >&2 + exit 1 +fi + +bad_symbols=$(${NM:-nm} "$objfile" | awk '$2 ~ /^[TtWw]$/ {print $3}' | grep -E '^(startup|exit|split|unlikely|hot|unknown)(\.|$)') + +if [ -n "$bad_symbols" ]; then + echo "$bad_symbols" | while read -r sym; do + echo "$objfile: error: $sym() function name creates ambiguity with -ffunction-sections" >&2 + done + exit 1 +fi + +exit 0 -- cgit v1.3.1