From 051074867434cc520c08f188479d4757dcfdaef8 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 12 Feb 2019 10:18:36 -0300 Subject: [PATCH] perf trace: Check if the 'fd' is negative when mapping it to pathname MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We were crashing when processing a negative fd: Program received signal SIGSEGV, Segmentation fault. 0x0000000000609bbf in syscall_arg__scnprintf_ioctl_cmd (bf=0x1172eca "", size=2038, arg=0x7fffffff8360) at trace/beauty/ioctl.c:182 182 if (file->dev_maj == USB_DEVICE_MAJOR) Missing separate debuginfos, use: dnf debuginfo-install bzip2-libs-1.0.6-28.fc29.x86_64 elfutils-libelf-0.174-5.fc29.x86_64 elfutils-libs-0.174-5.fc29.x86_64 glib2-2.58.3-1.fc29.x86_64 libbabeltrace-1.5.6-1.fc29.x86_64 libunwind-1.2.1-6.fc29.x86_64 libuuid-2.32.1-1.fc29.x86_64 libxcrypt-4.4.3-2.fc29.x86_64 numactl-libs-2.0.12-1.fc29.x86_64 openssl-libs-1.1.1a-1.fc29.x86_64 pcre-8.42-6.fc29.x86_64 perl-libs-5.28.1-427.fc29.x86_64 popt-1.16-15.fc29.x86_64 python2-libs-2.7.15-11.fc29.x86_64 slang-2.3.2-4.fc29.x86_64 xz-libs-5.2.4-3.fc29.x86_64 (gdb) bt #0 0x0000000000609bbf in syscall_arg__scnprintf_ioctl_cmd (bf=0x1172eca "", size=2038, arg=0x7fffffff8360) at trace/beauty/ioctl.c:182 #1 0x000000000048e295 in syscall__scnprintf_val (sc=0x123b500, bf=0x1172eca "", size=2038, arg=0x7fffffff8360, val=21519) at builtin-trace.c:1594 #2 0x000000000048e60d in syscall__scnprintf_args (sc=0x123b500, bf=0x1172ec6 "-1, ", size=2042, args=0x7ffff6a7c034 "\377\377\377\377", augmented_args=0x7ffff6a7c064, augmented_args_size=4, trace=0x7fffffffa8d0, thread=0x1175cd0) at builtin-trace.c:1661 #3 0x000000000048f04e in trace__sys_enter (trace=0x7fffffffa8d0, evsel=0xb260b0, event=0x7ffff6a7bfe8, sample=0x7fffffff84f0) at builtin-trace.c:1880 #4 0x00000000004915a4 in trace__handle_event (trace=0x7fffffffa8d0, event=0x7ffff6a7bfe8, sample=0x7fffffff84f0) at builtin-trace.c:2590 #5 0x0000000000491eed in __trace__deliver_event (trace=0x7fffffffa8d0, event=0x7ffff6a7bfe8) at builtin-trace.c:2818 #6 0x0000000000492030 in trace__deliver_event (trace=0x7fffffffa8d0, event=0x7ffff6a7bfe8) at builtin-trace.c:2845 #7 0x0000000000492896 in trace__run (trace=0x7fffffffa8d0, argc=0, argv=0x7fffffffdb58) at builtin-trace.c:3040 #8 0x000000000049603a in cmd_trace (argc=0, argv=0x7fffffffdb58) at builtin-trace.c:3952 #9 0x00000000004d5103 in main (argc=1, argv=0x7fffffffdb58) at perf.c:474 (gdb) p fd $1 = -1 (gdb) p file $7 = (struct file *) 0xfffffffffffffff0 (gdb) p ((struct thread_trace *)arg->thread)->files.table + fd $8 = (struct file *) 0xfffffffffffffff0 (gdb) Check for that and return NULL instead. This problem was introduced recently, the other codepaths leading to thread_trace__files_entry() check for negative fds, like thread__fd_path(), but we need to do it at thread_trace__files_entry() as more users are now calling it directly. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Luis Cláudio Gonçalves Cc: Namhyung Kim Cc: Wang Nan Fixes: 2d473389f87a ("perf trace beauty: Export function to get the files for a thread") Link: https://lkml.kernel.org/n/tip-oq7bvaaf07gsd4yqty3107u2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index b4e420c41831..a9b51f59ab54 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1041,6 +1041,9 @@ static const size_t trace__entry_str_size = 2048; static struct file *thread_trace__files_entry(struct thread_trace *ttrace, int fd) { + if (fd < 0) + return NULL; + if (fd > ttrace->files.max) { struct file *nfiles = realloc(ttrace->files.table, (fd + 1) * sizeof(struct file)); -- 2.11.0