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| author | Ali Ahmet Memis <ali@iusegentoo.com> | 2026-08-21 01:45:27 +0000 |
|---|---|---|
| committer | Stafford Horne <shorne@gmail.com> | 2026-08-29 07:32:26 +0100 |
| commit | 78004e9a87f240df03e2f73120d291763c32e0a7 (patch) | |
| tree | 137c22dd795222931b9d2bf2501d37cd766741aa /tools/perf/util/evswitch.h | |
| download | linux-stable-78004e9a87f240df03e2f73120d291763c32e0a7.tar.gz linux-stable-78004e9a87f240df03e2f73120d291763c32e0a7.zip | |
openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted
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 <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Diffstat (limited to 'tools/perf/util/evswitch.h')
| -rw-r--r-- | tools/perf/util/evswitch.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/tools/perf/util/evswitch.h b/tools/perf/util/evswitch.h new file mode 100644 index 000000000..8ffdbe526 --- /dev/null +++ b/tools/perf/util/evswitch.h @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (C) 2019, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com> +#ifndef __PERF_EVSWITCH_H +#define __PERF_EVSWITCH_H 1 + +#include <stdbool.h> +#include <stdio.h> + +struct evsel; +struct evlist; + +struct evswitch { + struct evsel *on, *off; + const char *on_name, *off_name; + bool discarding; + bool show_on_off_events; +}; + +int evswitch__init(struct evswitch *evswitch, struct evlist *evlist, FILE *fp); + +bool evswitch__discard(struct evswitch *evswitch, struct evsel *evsel); + +#define OPTS_EVSWITCH(evswitch) \ + OPT_STRING(0, "switch-on", &(evswitch)->on_name, \ + "event", "Consider events after the occurrence of this event"), \ + OPT_STRING(0, "switch-off", &(evswitch)->off_name, \ + "event", "Stop considering events after the occurrence of this event"), \ + OPT_BOOLEAN(0, "show-on-off-events", &(evswitch)->show_on_off_events, \ + "Show the on/off switch events, used with --switch-on and --switch-off") + +#endif /* __PERF_EVSWITCH_H */ |