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/block-range.h | 76 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 tools/perf/util/block-range.h (limited to 'tools/perf/util/block-range.h') diff --git a/tools/perf/util/block-range.h b/tools/perf/util/block-range.h new file mode 100644 index 000000000..ec0fb534b --- /dev/null +++ b/tools/perf/util/block-range.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_BLOCK_RANGE_H +#define __PERF_BLOCK_RANGE_H + +#include +#include +#include + +struct symbol; + +/* + * struct block_range - non-overlapping parts of basic blocks + * @node: treenode + * @start: inclusive start of range + * @end: inclusive end of range + * @is_target: @start is a jump target + * @is_branch: @end is a branch instruction + * @coverage: number of blocks that cover this range + * @taken: number of times the branch is taken (requires @is_branch) + * @pred: number of times the taken branch was predicted + */ +struct block_range { + struct rb_node node; + + struct symbol *sym; + + u64 start; + u64 end; + + int is_target, is_branch; + + u64 coverage; + u64 entry; + u64 taken; + u64 pred; +}; + +static inline struct block_range *block_range__next(struct block_range *br) +{ + struct rb_node *n = rb_next(&br->node); + if (!n) + return NULL; + return rb_entry(n, struct block_range, node); +} + +struct block_range_iter { + struct block_range *start; + struct block_range *end; +}; + +static inline struct block_range *block_range_iter(struct block_range_iter *iter) +{ + return iter->start; +} + +static inline bool block_range_iter__next(struct block_range_iter *iter) +{ + if (iter->start == iter->end) + return false; + + iter->start = block_range__next(iter->start); + return true; +} + +static inline bool block_range_iter__valid(struct block_range_iter *iter) +{ + if (!iter->start || !iter->end) + return false; + return true; +} + +extern struct block_range *block_range__find(u64 addr); +extern struct block_range_iter block_range__create(u64 start, u64 end); +extern double block_range__coverage(struct block_range *br); + +#endif /* __PERF_BLOCK_RANGE_H */ -- cgit v1.3.1