On 2022/11/26 0:34, Xin Long wrote:
, On Thu, Nov 24, 2022 at 9:59 PM 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") Reported-by: syzbot+29c402e56c4760763cc0@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx> --- 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 | 21 +++++++++++++++------ net/sctp/stream_sched.c | 5 +++++ net/sctp/stream_sched_prio.c | 19 +++++++++++++++++++ net/sctp/stream_sched_rr.c | 5 +++++ 5 files changed, 46 insertions(+), 6 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..30bf9ba10f8e 100644 --- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -52,6 +52,17 @@ 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); + + if (SCTP_SO(stream, sid)->ext) { + sched->free_sid(stream, sid); + kfree(SCTP_SO(stream, sid)->ext); + SCTP_SO(stream, sid)->ext = NULL; + } +} +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; } This will look better to me./* 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 +87,8 @@ 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); }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; } We should replace this one too so that all ext frees go to the same function. That's all from me. Thanks.
Hi Long: Thank you for your review. I will send V4. Zhengchao Shao
static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt, @@ -174,9 +183,9 @@ 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
