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/context-analysis-suppression.txt | 34 ++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 scripts/context-analysis-suppression.txt (limited to 'scripts/context-analysis-suppression.txt') diff --git a/scripts/context-analysis-suppression.txt b/scripts/context-analysis-suppression.txt new file mode 100644 index 000000000..1c51b6153 --- /dev/null +++ b/scripts/context-analysis-suppression.txt @@ -0,0 +1,34 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# The suppressions file should only match common paths such as header files. +# For individual subsytems use Makefile directive CONTEXT_ANALYSIS := [yn]. +# +# The suppressions are ignored when CONFIG_WARN_CONTEXT_ANALYSIS_ALL is +# selected. + +[thread-safety] +src:*arch/*/include/* +src:*include/acpi/* +src:*include/asm-generic/* +src:*include/linux/* +src:*include/net/* + +# Opt-in headers: +src:*include/linux/bit_spinlock.h=emit +src:*include/linux/cleanup.h=emit +src:*include/linux/kref.h=emit +src:*include/linux/list*.h=emit +src:*include/linux/local_lock*.h=emit +src:*include/linux/lockdep.h=emit +src:*include/linux/mutex*.h=emit +src:*include/linux/rcupdate.h=emit +src:*include/linux/refcount.h=emit +src:*include/linux/rhashtable.h=emit +src:*include/linux/rtmutex*.h=emit +src:*include/linux/rwlock*.h=emit +src:*include/linux/rwsem.h=emit +src:*include/linux/sched*=emit +src:*include/linux/seqlock*.h=emit +src:*include/linux/spinlock*.h=emit +src:*include/linux/srcu*.h=emit +src:*include/linux/ww_mutex.h=emit -- cgit v1.3.1