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author | Xin Long <lucien.xin@gmail.com> | 2023-02-22 12:07:21 -0500 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-11 13:55:26 +0100 |
commit | 03c3a5584a0a29821e59b7834635ce823050caaa (patch) | |
tree | 8d78c8acdf350188ab137658f33a20d71f2fc611 /include | |
parent | d28467230dd9b9d560e1003a5c5c58d3ddf457c0 (diff) | |
download | linux-03c3a5584a0a29821e59b7834635ce823050caaa.tar.gz |
sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop
[ Upstream commit 68ba44639537de6f91fe32783766322d41848127 ] 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: 9ed7bfc79542 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/net/sctp/structs.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 350f250b0dc7..00ee9eb601a6 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -1409,6 +1409,7 @@ struct sctp_stream_priorities { /* The next stream in line */ struct sctp_stream_out_ext *next; __u16 prio; + __u16 users; }; struct sctp_stream_out_ext { |