Re: [PATCH] tools lib traceevent: Fix memory leak in process_dynamic_array_len

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Thu, Jul 30, 2020 at 05:28:43PM -0400, Steven Rostedt escreveu:
> 
> Arnaldo,
> 
> Can you pull this into your tree under urgent?
> 
>  https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com/
> 
> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Sure, will get it and try and send today,

- Arnaldo
 
> -- Steve
> 
> 
> On Thu, 30 Jul 2020 11:02:36 -0400
> Philippe Duplessis-Guindon <pduplessis@efficios.com> wrote:
> 
> > I compiled with AddressSanitizer and I had these memory leaks while I
> > was using the tep_parse_format function:
> > 
> >     Direct leak of 28 byte(s) in 4 object(s) allocated from:
> >         #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe)
> >         #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985
> >         #2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140
> >         #3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206
> >         #4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291
> >         #5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299
> >         #6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849
> >         #7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161
> >         #8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207
> >         #9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786
> >         #10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285
> >         #11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369
> >         #12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335
> >         #13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389
> >         #14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431
> >         #15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251
> >         #16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284
> >         #17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593
> >         #18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727
> >         #19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048
> >         #20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127
> >         #21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152
> >         #22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252
> >         #23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347
> >         #24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461
> >         #25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673
> >         #26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
> > 
> > The token variable in the process_dynamic_array_len function is
> > allocated in the read_expect_type function, but is not freed before
> > calling the read_token function.
> > 
> > Free the token variable before calling read_token in order to plug the
> > leak.
> > 
> > Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com>
> > ---
> >  tools/lib/traceevent/event-parse.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
> > index 5b36c589a029..ba4f33804af1 100644
> > --- a/tools/lib/traceevent/event-parse.c
> > +++ b/tools/lib/traceevent/event-parse.c
> > @@ -2861,6 +2861,7 @@ process_dynamic_array_len(struct tep_event *event, struct tep_print_arg *arg,
> >  	if (read_expected(TEP_EVENT_DELIM, ")") < 0)
> >  		goto out_err;
> >  
> > +	free_token(token);
> >  	type = read_token(&token);
> >  	*tok = token;
> >