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/units.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 tools/perf/util/units.c (limited to 'tools/perf/util/units.c') diff --git a/tools/perf/util/units.c b/tools/perf/util/units.c new file mode 100644 index 000000000..0bbacf5a2 --- /dev/null +++ b/tools/perf/util/units.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "units.h" +#include +#include +#include +#include +#include +#include + +unsigned long parse_tag_value(const char *str, struct parse_tag *tags) +{ + struct parse_tag *i = tags; + + while (i->tag) { + const char *s = strchr(str, i->tag); + + if (s) { + unsigned long int value; + char *endptr; + + value = strtoul(str, &endptr, 10); + if (s != endptr) + break; + + if (value > ULONG_MAX / i->mult) + break; + value *= i->mult; + return value; + } + i++; + } + + return (unsigned long) -1; +} + +double convert_unit_double(double value, char *unit) +{ + *unit = ' '; + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'K'; + } + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'M'; + } + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'G'; + } + + return value; +} + +unsigned long convert_unit(unsigned long value, char *unit) +{ + double v = convert_unit_double((double)value, unit); + + return (unsigned long)v; +} + +int unit_number__scnprintf(char *buf, size_t size, u64 n) +{ + char unit[] = "BKMG"; + int i = 0; + + while (((n / 1024) > 1) && (i < 3)) { + n /= 1024; + i++; + } + + return scnprintf(buf, size, "%" PRIu64 "%c", n, unit[i]); +} -- cgit v1.3.1