From: Duoming Zhou duoming@zju.edu.cn
[ Upstream commit b89fc26f741d9f9efb51cba3e9b241cf1380ec5a ]
There are sleep in atomic context bugs in timer handlers of sctp such as sctp_generate_t3_rtx_event(), sctp_generate_probe_event(), sctp_generate_t1_init_event(), sctp_generate_timeout_event(), sctp_generate_t3_rtx_event() and so on.
The root cause is sctp_sched_prio_init_sid() with GFP_KERNEL parameter that may sleep could be called by different timer handlers which is in interrupt context.
One of the call paths that could trigger bug is shown below:
(interrupt context) sctp_generate_probe_event sctp_do_sm sctp_side_effects sctp_cmd_interpreter sctp_outq_teardown sctp_outq_init sctp_sched_set_sched n->init_sid(..,GFP_KERNEL) sctp_sched_prio_init_sid //may sleep
This patch changes gfp_t parameter of init_sid in sctp_sched_set_sched() from GFP_KERNEL to GFP_ATOMIC in order to prevent sleep in atomic context bugs.
Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Signed-off-by: Duoming Zhou duoming@zju.edu.cn Acked-by: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Link: https://lore.kernel.org/r/20220723015809.11553-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/sctp/stream_sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sctp/stream_sched.c b/net/sctp/stream_sched.c index a6c04a94b08f..3a5c0d00e96c 100644 --- a/net/sctp/stream_sched.c +++ b/net/sctp/stream_sched.c @@ -178,7 +178,7 @@ int sctp_sched_set_sched(struct sctp_association *asoc, if (!SCTP_SO(&asoc->stream, i)->ext) continue;
- ret = n->init_sid(&asoc->stream, i, GFP_KERNEL); + ret = n->init_sid(&asoc->stream, i, GFP_ATOMIC); if (ret) goto err; }