diff options
| author | Wang Nan <wangnan0@huawei.com> | 2015-12-07 02:35:45 +0000 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-12-07 12:02:11 -0300 |
| commit | 837eeb7569bf2b3bd3b1b82e0e61edb19811036e (patch) | |
| tree | de1528f1c9cd6eda7a9f51cfca8f69ccfb5d2a65 /tools | |
| parent | c8319c9d0d4a61b346aa9b30fb93978f1a355606 (diff) | |
perf hists browser: Add NULL pointer check to prevent crash
Before this patch we can trigger a segfault by following steps:
Step 0: Use 'perf record' to generate a perf.data without callchain
Step 1: perf report
Step 2: Use UP/DOWN to select an entry, don't press 'ENTER'
Step 3: Use '/' to filter symbols, use a filter which returns
empty result
Step 4: Press 'ENTER' (notice here that the old selection is still
there. This is another problem)
Step 5: Press 'ENTER' to annotate that symbol
Step 6: Press 'LEFT' to go out.
Result: segfault:
perf: Segmentation fault
-------- backtrace --------
/home/wangnan/perf[0x53e568]
/lib64/libc.so.6(+0x3545f)[0x7fba75d3245f]
/home/wangnan/perf[0x537516]
/home/wangnan/perf[0x533fef]
/home/wangnan/perf[0x53b347]
/home/wangnan/perf(perf_evlist__tui_browse_hists+0x96)[0x53d206]
/home/wangnan/perf(cmd_report+0x1b9f)[0x442c7f]
/home/wangnan/perf[0x47efa2]
/home/wangnan/perf(main+0x5f5)[0x432fa5]
/lib64/libc.so.6(__libc_start_main+0xf4)[0x7fba75d1ebd4]
/home/wangnan/perf[0x4330d4]
This is because in this case 'nd' could be NULL in
ui_browser__hists_seek(), but that function never checks it.
This patch adds checker for potential NULL pointer in that function.
After this patch the above steps won't segfault.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1449455746-41952-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/ui/browsers/hists.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c index fa9eb92c9e24..932e13d015b9 100644 --- a/tools/perf/ui/browsers/hists.c +++ b/tools/perf/ui/browsers/hists.c @@ -1033,6 +1033,9 @@ static void ui_browser__hists_seek(struct ui_browser *browser, * and stop when we printed enough lines to fill the screen. */ do_offset: + if (!nd) + return; + if (offset > 0) { do { h = rb_entry(nd, struct hist_entry, rb_node); |