On Thu, Nov 24, 2022 at 8:22 AM Zhengchao Shao <shaozhengchao@xxxxxxxxxx> wrote: > > 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 <shaozhengchao@xxxxxxxxxx> > --- > 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; It will be better to move "!SCTP_SO(stream, sid)->ext" check to sctp_stream_free_ext(). > + > + 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, Please also add .free_sid for sctp_sched_fcfs/rr, although they could be empty functions. Thanks. > .free = sctp_sched_prio_free, > .enqueue = sctp_sched_prio_enqueue, > .dequeue = sctp_sched_prio_dequeue, > -- > 2.17.1 >
