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/ui/util.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 tools/perf/ui/util.c (limited to 'tools/perf/ui/util.c') diff --git a/tools/perf/ui/util.c b/tools/perf/ui/util.c new file mode 100644 index 000000000..1d38ddf01 --- /dev/null +++ b/tools/perf/ui/util.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "util.h" +#include "../util/debug.h" +#include + +/* + * Default error logging functions + */ +static int perf_stdio__error(const char *format, va_list args) +{ + fprintf(stderr, "Error:\n"); + vfprintf(stderr, format, args); + return 0; +} + +static int perf_stdio__warning(const char *format, va_list args) +{ + if (quiet) + return 0; + + fprintf(stderr, "Warning:\n"); + vfprintf(stderr, format, args); + return 0; +} + +static struct perf_error_ops default_eops = +{ + .error = perf_stdio__error, + .warning = perf_stdio__warning, +}; + +static struct perf_error_ops *perf_eops = &default_eops; + + +int ui__error(const char *format, ...) +{ + int ret; + va_list args; + + va_start(args, format); + ret = perf_eops->error(format, args); + va_end(args); + + return ret; +} + +int ui__warning(const char *format, ...) +{ + int ret; + va_list args; + if (quiet) + return 0; + + va_start(args, format); + ret = perf_eops->warning(format, args); + va_end(args); + + return ret; +} + +/** + * perf_error__register - Register error logging functions + * @eops: The pointer to error logging function struct + * + * Register UI-specific error logging functions. Before calling this, + * other logging functions should be unregistered, if any. + */ +int perf_error__register(struct perf_error_ops *eops) +{ + if (perf_eops != &default_eops) + return -1; + + perf_eops = eops; + return 0; +} + +/** + * perf_error__unregister - Unregister error logging functions + * @eops: The pointer to error logging function struct + * + * Unregister already registered error logging functions. + */ +int perf_error__unregister(struct perf_error_ops *eops) +{ + if (perf_eops != eops) + return -1; + + perf_eops = &default_eops; + return 0; +} -- cgit v1.3.1