When sctp_stream_outq_migrate() is called to release stream out resources,
the memory pointed to by prio_head in stream out is not released.
The memory leak information is as follows:
unreferenced object 0xffff88801fe79f80 (size 64):
comm "sctp_repo", pid 7957, jiffies 4294951704 (age 36.480s)
hex dump (first 32 bytes):
80 9f e7 1f 80 88 ff ff 80 9f e7 1f 80 88 ff ff ................
90 9f e7 1f 80 88 ff ff 90 9f e7 1f 80 88 ff ff ................
backtrace:
[<ffffffff81b215c6>] kmalloc_trace+0x26/0x60
[<ffffffff88ae517c>] sctp_sched_prio_set+0x4cc/0x770
[<ffffffff88ad64f2>] sctp_stream_init_ext+0xd2/0x1b0
[<ffffffff88aa2604>] sctp_sendmsg_to_asoc+0x1614/0x1a30
[<ffffffff88ab7ff1>] sctp_sendmsg+0xda1/0x1ef0
[<ffffffff87f765ed>] inet_sendmsg+0x9d/0xe0
[<ffffffff8754b5b3>] sock_sendmsg+0xd3/0x120
[<ffffffff8755446a>] __sys_sendto+0x23a/0x340
[<ffffffff87554651>] __x64_sys_sendto+0xe1/0x1b0
[<ffffffff89978b49>] do_syscall_64+0x39/0xb0
[<ffffffff89a0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Link: https://syzkaller.appspot.com/bug?exrid=29c402e56c4760763cc0
Fixes: 637784ade221 ("sctp: introduce priority based stream scheduler")
Reported-by: syzbot+29c402e56c4760763cc0@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
---
v4: use .free_sid to free a new stream
v3: also add .free_sid for sctp_sched_fcfs/rr and make sure only free
once in sctp_stream_free()
v2: add .free_sid hook function and use it to free a stream
---
include/net/sctp/stream_sched.h | 2 ++
net/sctp/stream.c | 25 ++++++++++++++++++-------
net/sctp/stream_sched.c | 5 +++++
net/sctp/stream_sched_prio.c | 19 +++++++++++++++++++
net/sctp/stream_sched_rr.c | 5 +++++
5 files changed, 49 insertions(+), 7 deletions(-)
diff --git a/include/net/sctp/stream_sched.h b/include/net/sctp/stream_sched.h
index 01a70b27e026..65058faea4db 100644
--- a/include/net/sctp/stream_sched.h
+++ b/include/net/sctp/stream_sched.h
@@ -26,6 +26,8 @@ struct sctp_sched_ops {
int (*init)(struct sctp_stream *stream);
/* Init a stream */
int (*init_sid)(struct sctp_stream *stream, __u16 sid, gfp_t gfp);
+ /* free a stream */
+ void (*free_sid)(struct sctp_stream *stream, __u16 sid);
/* Frees the entire thing */
void (*free)(struct sctp_stream *stream);
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index ef9fceadef8d..ee6514af830f 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -52,6 +52,19 @@ static void sctp_stream_shrink_out(struct sctp_stream *stream, __u16 outcnt)
}
}
+static void sctp_stream_free_ext(struct sctp_stream *stream, __u16 sid)
+{
+ struct sctp_sched_ops *sched;
+
+ if (!SCTP_SO(stream, sid)->ext)
+ return;
+
+ sched = sctp_sched_ops_from_stream(stream);
+ sched->free_sid(stream, sid);
+ kfree(SCTP_SO(stream, sid)->ext);
+ SCTP_SO(stream, sid)->ext = NULL;
+}
+
/* Migrates chunks from stream queues to new stream queues if needed,
* but not across associations. Also, removes those chunks to streams
* higher than the new max.
@@ -70,16 +83,14 @@ static void sctp_stream_outq_migrate(struct sctp_stream *stream,
* sctp_stream_update will swap ->out pointers.
*/
for (i = 0; i < outcnt; i++) {
- kfree(SCTP_SO(new, i)->ext);
+ sctp_stream_free_ext(new, i);
SCTP_SO(new, i)->ext = SCTP_SO(stream, i)->ext;
SCTP_SO(stream, i)->ext = NULL;
}
}
- for (i = outcnt; i < stream->outcnt; i++) {
- kfree(SCTP_SO(stream, i)->ext);
- SCTP_SO(stream, i)->ext = NULL;
- }
+ for (i = outcnt; i < stream->outcnt; i++)
+ sctp_stream_free_ext(stream, i);
}
static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
@@ -174,9 +185,9 @@ void sctp_stream_free(struct sctp_stream *stream)
struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
int i;
- sched->free(stream);
+ sched->unsched_all(stream);
for (i = 0; i < stream->outcnt; i++)
- kfree(SCTP_SO(stream, i)->ext);
+ sctp_stream_free_ext(stream, i);
genradix_free(&stream->out);
genradix_free(&stream->in);
}
diff --git a/net/sctp/stream_sched.c b/net/sctp/stream_sched.c
index 1ad565ed5627..7c8f9d89e16a 100644
--- a/net/sctp/stream_sched.c
+++ b/net/sctp/stream_sched.c
@@ -46,6 +46,10 @@ static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid,
return 0;
}
+static void sctp_sched_fcfs_free_sid(struct sctp_stream *stream, __u16 sid)
+{
+}
+
static void sctp_sched_fcfs_free(struct sctp_stream *stream)
{
}
@@ -96,6 +100,7 @@ static struct sctp_sched_ops sctp_sched_fcfs = {
.get = sctp_sched_fcfs_get,
.init = sctp_sched_fcfs_init,
.init_sid = sctp_sched_fcfs_init_sid,
+ .free_sid = sctp_sched_fcfs_free_sid,
.free = sctp_sched_fcfs_free,
.enqueue = sctp_sched_fcfs_enqueue,
.dequeue = sctp_sched_fcfs_dequeue,
diff --git a/net/sctp/stream_sched_prio.c b/net/sctp/stream_sched_prio.c
index 80b5a2c4cbc7..4fc9f2923ed1 100644
--- a/net/sctp/stream_sched_prio.c
+++ b/net/sctp/stream_sched_prio.c
@@ -204,6 +204,24 @@ static int sctp_sched_prio_init_sid(struct sctp_stream *stream, __u16 sid,
return sctp_sched_prio_set(stream, sid, 0, gfp);
}
+static void sctp_sched_prio_free_sid(struct sctp_stream *stream, __u16 sid)
+{
+ struct sctp_stream_priorities *prio = SCTP_SO(stream, sid)->ext->prio_head;
+ int i;
+
+ if (!prio)
+ return;
+
+ SCTP_SO(stream, sid)->ext->prio_head = NULL;
+ for (i = 0; i < stream->outcnt; i++) {
+ if (SCTP_SO(stream, i)->ext &&
+ SCTP_SO(stream, i)->ext->prio_head == prio)
+ return;
+ }
+
+ kfree(prio);
+}
+
static void sctp_sched_prio_free(struct sctp_stream *stream)
{
struct sctp_stream_priorities *prio, *n;
@@ -323,6 +341,7 @@ static struct sctp_sched_ops sctp_sched_prio = {
.get = sctp_sched_prio_get,
.init = sctp_sched_prio_init,
.init_sid = sctp_sched_prio_init_sid,
+ .free_sid = sctp_sched_prio_free_sid,
.free = sctp_sched_prio_free,
.enqueue = sctp_sched_prio_enqueue,
.dequeue = sctp_sched_prio_dequeue,
diff --git a/net/sctp/stream_sched_rr.c b/net/sctp/stream_sched_rr.c
index ff425aed62c7..cc444fe0d67c 100644
--- a/net/sctp/stream_sched_rr.c
+++ b/net/sctp/stream_sched_rr.c
@@ -90,6 +90,10 @@ static int sctp_sched_rr_init_sid(struct sctp_stream *stream, __u16 sid,
return 0;
}
+static void sctp_sched_rr_free_sid(struct sctp_stream *stream, __u16 sid)
+{
+}
+
static void sctp_sched_rr_free(struct sctp_stream *stream)
{
sctp_sched_rr_unsched_all(stream);
@@ -177,6 +181,7 @@ static struct sctp_sched_ops sctp_sched_rr = {
.get = sctp_sched_rr_get,
.init = sctp_sched_rr_init,
.init_sid = sctp_sched_rr_init_sid,
+ .free_sid = sctp_sched_rr_free_sid,
.free = sctp_sched_rr_free,
.enqueue = sctp_sched_rr_enqueue,
.dequeue = sctp_sched_rr_dequeue,
--
2.17.1
