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/libdw.h | 58 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 tools/perf/util/libdw.h (limited to 'tools/perf/util/libdw.h') diff --git a/tools/perf/util/libdw.h b/tools/perf/util/libdw.h new file mode 100644 index 000000000..b12094737 --- /dev/null +++ b/tools/perf/util/libdw.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef PERF_LIBDW_H +#define PERF_LIBDW_H + +#include + +struct dso; +struct inline_node; +struct symbol; + +#ifdef HAVE_LIBDW_SUPPORT +/* + * libdw__addr2line - Convert address to source location using libdw + * @addr: Address to resolve + * @file: Pointer to return filename (caller must free) + * @line_nr: Pointer to return line number + * @dso: The dso struct + * @unwind_inlines: Whether to unwind inline function calls + * @node: Inline node list to append to + * @sym: The symbol associated with the address + * + * This function initializes a Dwfl context for the DSO if not already present, + * finds the source line information for the given address, and optionally + * resolves inline function call chains. + * + * Returns 1 on success (found), 0 on failure (not found). + */ +int libdw__addr2line(u64 addr, char **file, + unsigned int *line_nr, struct dso *dso, + bool unwind_inlines, struct inline_node *node, + struct symbol *sym); + +/* + * dso__free_libdw - Free libdw resources associated with the DSO + * @dso: The dso to free resources for + * + * This function cleans up the Dwfl context used for addr2line lookups. + */ +void dso__free_libdw(struct dso *dso); + +#else /* HAVE_LIBDW_SUPPORT */ + +static inline int libdw__addr2line(u64 addr __maybe_unused, char **file __maybe_unused, + unsigned int *line_nr __maybe_unused, + struct dso *dso __maybe_unused, + bool unwind_inlines __maybe_unused, + struct inline_node *node __maybe_unused, + struct symbol *sym __maybe_unused) +{ + return 0; +} + +static inline void dso__free_libdw(struct dso *dso __maybe_unused) +{ +} +#endif /* HAVE_LIBDW_SUPPORT */ + +#endif /* PERF_LIBDW_H */ -- cgit v1.3.1