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 --- tools/perf/util/mem2node.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 tools/perf/util/mem2node.h (limited to 'tools/perf/util/mem2node.h') diff --git a/tools/perf/util/mem2node.h b/tools/perf/util/mem2node.h new file mode 100644 index 000000000..8dfa2b58d --- /dev/null +++ b/tools/perf/util/mem2node.h @@ -0,0 +1,20 @@ +#ifndef __MEM2NODE_H +#define __MEM2NODE_H + +#include +#include + +struct perf_env; +struct phys_entry; + +struct mem2node { + struct rb_root root; + struct phys_entry *entries; + int cnt; +}; + +int mem2node__init(struct mem2node *map, struct perf_env *env); +void mem2node__exit(struct mem2node *map); +int mem2node__node(struct mem2node *map, u64 addr); + +#endif /* __MEM2NODE_H */ -- cgit v1.3.1