2009-03-23 08:27:15

by Tom Zanussi

Subject: [PATCH] tracing/filters: fix bug in copy_pred()

When making a copy of the predicate, pred->field_name needs to be
duplicated in the copy as well, otherwise bad things can happen due to
later multiple frees of the same string.

This affects only per-subsystem event filtering.

Signed-off-by: Tom Zanussi <[email protected]>

---
kernel/trace/trace_events_filter.c | 12 ++++++++++--
1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index c4a413b..fd01d80 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -276,11 +276,19 @@ static struct filter_pred *copy_pred(struct filter_pred *pred)
return NULL;

memcpy(new_pred, pred, sizeof(*pred));
+
+ if (pred->field_name) {
+ new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
+ if (!new_pred->field_name) {
+ kfree(new_pred);
+ return NULL;
+ }
+ }
+
if (pred->str_val) {
new_pred->str_val = kstrdup(pred->str_val, GFP_KERNEL);
- new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
if (!new_pred->str_val) {
- kfree(new_pred);
+ filter_free_pred(new_pred);
return NULL;
}
}
--
1.5.6.3

2009-03-23 08:34:43

by Tom Zanussi

Subject: [tip:tracing/filters] tracing/filters: fix bug in copy_pred()

Commit-ID: ee6cdabc820a29bd607f38d9cb335c3ceddc673b
Gitweb: http://git.kernel.org/tip/ee6cdabc820a29bd607f38d9cb335c3ceddc673b
Author: Tom Zanussi <[email protected]>
AuthorDate: Mon, 23 Mar 2009 03:26:42 -0500
Committer: Ingo Molnar <[email protected]>
CommitDate: Mon, 23 Mar 2009 09:30:36 +0100

tracing/filters: fix bug in copy_pred()

Impact: fix potential crash on subsystem filter expression freeing

When making a copy of the predicate, pred->field_name needs to be
duplicated in the copy as well, otherwise bad things can happen due to
later multiple frees of the same string.

This affects only per-subsystem event filtering.

Signed-off-by: Tom Zanussi <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker <[email protected]>
LKML-Reference: <1237796802.7527.39.camel@charm-linux>
Signed-off-by: Ingo Molnar <[email protected]>


---
kernel/trace/trace_events_filter.c | 12 ++++++++++--
1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index c4a413b..fd01d80 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -276,11 +276,19 @@ static struct filter_pred *copy_pred(struct filter_pred *pred)
return NULL;

memcpy(new_pred, pred, sizeof(*pred));
+
+ if (pred->field_name) {
+ new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
+ if (!new_pred->field_name) {
+ kfree(new_pred);
+ return NULL;
+ }
+ }
+
if (pred->str_val) {
new_pred->str_val = kstrdup(pred->str_val, GFP_KERNEL);
- new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
if (!new_pred->str_val) {
- kfree(new_pred);
+ filter_free_pred(new_pred);
return NULL;
}
}