[PATCH net v2] sctp: fix memory leak in sctp_stream_outq_migrate()
From: Zhengchao Shao <hidden>
Date: 2022-11-24 13:04:48
Also in:
linux-sctp
Subsystem:
networking [general], sctp protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds
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: Fixes: 637784ade221 ("sctp: introduce priority based stream scheduler")
Signed-off-by: Zhengchao Shao <redacted>
---
v2: add .free_sid hook function and use it to free a stream
---
include/net/sctp/stream_sched.h | 2 ++
net/sctp/stream.c | 15 +++++++++++----
net/sctp/stream_sched_prio.c | 20 ++++++++++++++++++++
3 files changed, 33 insertions(+), 4 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..0a704bbf1155 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c@@ -52,6 +52,15 @@ 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 = 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.
@@ -76,10 +85,8 @@ static void sctp_stream_outq_migrate(struct sctp_stream *stream, } } - 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,
diff --git a/net/sctp/stream_sched_prio.c b/net/sctp/stream_sched_prio.c
index 80b5a2c4cbc7..e9cc71b93e90 100644
--- a/net/sctp/stream_sched_prio.c
+++ b/net/sctp/stream_sched_prio.c@@ -204,6 +204,25 @@ 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; + int i; + + if (!SCTP_SO(stream, sid)->ext || !SCTP_SO(stream, sid)->ext->prio_head) + return; + + prio = SCTP_SO(stream, sid)->ext->prio_head; + 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 +342,7 @@ 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,
--
2.17.1