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authorChengfeng Ye <dg573847474@gmail.com>2023-06-27 12:03:40 +0000
committerPaolo Abeni <pabeni@redhat.com>2023-06-29 11:49:42 +0200
commit6feb37b3b06e9049e20dcf7e23998f92c9c5be9a (patch)
treea1e1728562d5fab1ccb07116f9963c5b8ce4a717 /net
parent7a8227b2e76be506b2ac64d2beac950ca04892a5 (diff)
sctp: fix potential deadlock on &net->sctp.addr_wq_lock
As &net->sctp.addr_wq_lock is also acquired by the timer sctp_addr_wq_timeout_handler() in protocal.c, the same lock acquisition at sctp_auto_asconf_init() seems should disable irq since it is called from sctp_accept() under process context. Possible deadlock scenario: sctp_accept() -> sctp_sock_migrate() -> sctp_auto_asconf_init() -> spin_lock(&net->sctp.addr_wq_lock) <timer interrupt> -> sctp_addr_wq_timeout_handler() -> spin_lock_bh(&net->sctp.addr_wq_lock); (deadlock here) This flaw was found using an experimental static analysis tool we are developing for irq-related deadlock. The tentative patch fix the potential deadlock by spin_lock_bh(). Signed-off-by: Chengfeng Ye <dg573847474@gmail.com> Fixes: 34e5b0118685 ("sctp: delay auto_asconf init until binding the first addr") Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/20230627120340.19432-1-dg573847474@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
-rw-r--r--net/sctp/socket.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 6554a357fe33..9388d98aebc0 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -364,9 +364,9 @@ static void sctp_auto_asconf_init(struct sctp_sock *sp)
struct net *net = sock_net(&sp->inet.sk);
if (net->sctp.default_auto_asconf) {
- spin_lock(&net->sctp.addr_wq_lock);
+ spin_lock_bh(&net->sctp.addr_wq_lock);
list_add_tail(&sp->auto_asconf_list, &net->sctp.auto_asconf_splist);
- spin_unlock(&net->sctp.addr_wq_lock);
+ spin_unlock_bh(&net->sctp.addr_wq_lock);
sp->do_auto_asconf = 1;
}
}