linux/include/net/sctp
Xin Long 68ba446395 sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop
With this refcnt added in sctp_stream_priorities, we don't need to
traverse all streams to check if the prio is used by other streams
when freeing one stream's prio in sctp_sched_prio_free_sid(). This
can avoid a nested loop (up to 65535 * 65535), which may cause a
stuck as Ying reported:

    watchdog: BUG: soft lockup - CPU#23 stuck for 26s! [ksoftirqd/23:136]
    Call Trace:
     <TASK>
     sctp_sched_prio_free_sid+0xab/0x100 [sctp]
     sctp_stream_free_ext+0x64/0xa0 [sctp]
     sctp_stream_free+0x31/0x50 [sctp]
     sctp_association_free+0xa5/0x200 [sctp]

Note that it doesn't need to use refcount_t type for this counter,
as its accessing is always protected under the sock lock.

v1->v2:
 - add a check in sctp_sched_prio_set to avoid the possible prio_head
   refcnt overflow.

Fixes: 9ed7bfc795 ("sctp: fix memory leak in sctp_stream_outq_migrate()")
Reported-by: Ying Xu <yinxu@redhat.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/825eb0c905cb864991eba335f4a2b780e543f06b.1677085641.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-23 12:59:40 -08:00
..
auth.h sctp: add sctp_auth_init and sctp_auth_free 2019-08-19 18:27:29 -07:00
checksum.h sctp: change to include linux/sctp.h in net/sctp/checksum.h 2022-11-17 21:43:34 -08:00
command.h sctp: add the probe timer in transport for PLPMTUD 2021-06-22 11:28:52 -07:00
constants.h sctp: move 198 addresses from unusable to private scope 2021-07-01 11:47:13 -07:00
sctp.h sctp: add dif and sdif check in asoc and ep lookup 2022-11-18 11:42:54 +00:00
sm.h sctp: fix transport encap_port update in sctp_vtag_verify 2021-10-15 11:21:10 +01:00
stream_interleave.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
stream_sched.h sctp: delete free member from struct sctp_sched_ops 2022-12-01 20:14:23 -08:00
structs.h sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop 2023-02-23 12:59:40 -08:00
tsnmap.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
ulpevent.h sctp: fix typo sctp_ulpevent_nofity_peer_addr_change 2020-05-27 15:08:02 -07:00
ulpqueue.h sctp: remove unnecessary NULL check in sctp_association_init() 2022-10-20 21:43:10 -07:00