perf ui browser: Don't save pointer to stack memory

[ Upstream commit 769e6a1 ]

ui_browser__show() is capturing the input title that is stack allocated
memory in hist_browser__run().

Avoid a use after return by strdup-ing the string.

Committer notes:

Further explanation from Ian Rogers:

My command line using tui is:
$ sudo bash -c 'rm /tmp/asan.log*; export
ASAN_OPTIONS="log_path=/tmp/asan.log"; /tmp/perf/perf mem record -a
sleep 1; /tmp/perf/perf mem report'
I then go to the perf annotate view and quit. This triggers the asan
error (from the log file):
```
==1254591==ERROR: AddressSanitizer: stack-use-after-return on address
0x7f2813331920 at pc 0x7f28180
65991 bp 0x7fff0a21c750 sp 0x7fff0a21bf10
READ of size 80 at 0x7f2813331920 thread T0
    #0 0x7f2818065990 in __interceptor_strlen
../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:461
    truenas#1 0x7f2817698251 in SLsmg_write_wrapped_string
(/lib/x86_64-linux-gnu/libslang.so.2+0x98251)
    truenas#2 0x7f28176984b9 in SLsmg_write_nstring
(/lib/x86_64-linux-gnu/libslang.so.2+0x984b9)
    truenas#3 0x55c94045b365 in ui_browser__write_nstring ui/browser.c:60
    truenas#4 0x55c94045c558 in __ui_browser__show_title ui/browser.c:266
    truenas#5 0x55c94045c776 in ui_browser__show ui/browser.c:288
    truenas#6 0x55c94045c06d in ui_browser__handle_resize ui/browser.c:206
    truenas#7 0x55c94047979b in do_annotate ui/browsers/hists.c:2458
    truenas#8 0x55c94047fb17 in evsel__hists_browse ui/browsers/hists.c:3412
    truenas#9 0x55c940480a0c in perf_evsel_menu__run ui/browsers/hists.c:3527
    truenas#10 0x55c940481108 in __evlist__tui_browse_hists ui/browsers/hists.c:3613
    truenas#11 0x55c9404813f7 in evlist__tui_browse_hists ui/browsers/hists.c:3661
    truenas#12 0x55c93ffa253f in report__browse_hists tools/perf/builtin-report.c:671
    truenas#13 0x55c93ffa58ca in __cmd_report tools/perf/builtin-report.c:1141
    truenas#14 0x55c93ffaf159 in cmd_report tools/perf/builtin-report.c:1805
    truenas#15 0x55c94000c05c in report_events tools/perf/builtin-mem.c:374
    truenas#16 0x55c94000d96d in cmd_mem tools/perf/builtin-mem.c:516
    truenas#17 0x55c9400e44ee in run_builtin tools/perf/perf.c:350
    truenas#18 0x55c9400e4a5a in handle_internal_command tools/perf/perf.c:403
    truenas#19 0x55c9400e4e22 in run_argv tools/perf/perf.c:447
    truenas#20 0x55c9400e53ad in main tools/perf/perf.c:561
    truenas#21 0x7f28170456c9 in __libc_start_call_main
../sysdeps/nptl/libc_start_call_main.h:58
    truenas#22 0x7f2817045784 in __libc_start_main_impl ../csu/libc-start.c:360
    truenas#23 0x55c93ff544c0 in _start (/tmp/perf/perf+0x19a4c0) (BuildId:
84899b0e8c7d3a3eaa67b2eb35e3d8b2f8cd4c93)

Address 0x7f2813331920 is located in stack of thread T0 at offset 32 in frame
    #0 0x55c94046e85e in hist_browser__run ui/browsers/hists.c:746

  This frame has 1 object(s):
    [32, 192) 'title' (line 747) <== Memory access at offset 32 is
inside this variable
HINT: this may be a false positive if your program uses some custom
stack unwind mechanism, swapcontext or vfork
```
hist_browser__run isn't on the stack so the asan error looks legit.
There's no clean init/exit on struct ui_browser so I may be trading a
use-after-return for a memory leak, but that seems look a good trade
anyway.

Fixes: 05e8b08 ("perf ui browser: Stop using 'self'")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Li Dong <lidong@vivo.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Paran Lee <p4ranlee@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sun Haiyong <sunhaiyong@loongson.cn>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240507183545.1236093-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

tools/perf/ui/browser.c

@@ -287,7 +287,8 @@ int ui_browser__show(struct ui_browser *browser, const char *title,
 	mutex_lock(&ui__lock);
 	__ui_browser__show_title(browser, title);
 
-	browser->title = title;
+	free(browser->title);
+	browser->title = strdup(title);
 	zfree(&browser->helpline);
 
 	va_start(ap, helpline);
@@ -304,6 +305,7 @@ void ui_browser__hide(struct ui_browser *browser)
 	mutex_lock(&ui__lock);
 	ui_helpline__pop();
 	zfree(&browser->helpline);
+	zfree(&browser->title);
 	mutex_unlock(&ui__lock);
 }
 

tools/perf/ui/browser.h

@@ -21,7 +21,7 @@ struct ui_browser {
 	u8	      extra_title_lines;
 	int	      current_color;
 	void	      *priv;
-	const char    *title;
+	char	      *title;
 	char	      *helpline;
 	const char    *no_samples_msg;
 	void 	      (*refresh_dimensions)(struct ui_browser *browser);