diff options
| author | Chengfeng Ye | 2023-06-27 12:03:40 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-07-19 16:22:00 +0200 |
| commit | 1aa5a6a6d28c77e364feaba35ff7f12d2d74fec1 (patch) | |
| tree | 6a1b720dfb0ffeb4ca14acda666ae41990c1294f /net | |
| parent | 9dbcfc01d6868b81c440f35a4c0eef9ed86f34c3 (diff) | |
sctp: fix potential deadlock on &net->sctp.addr_wq_lock
[ Upstream commit 6feb37b3b06e9049e20dcf7e23998f92c9c5be9a ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sctp/socket.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index e1011311bc87..c806d272107a 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -363,9 +363,9 @@ 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; } } |