From: <gregkh@linuxfoundation.org>
To: vegard.nossum@oracle.com, davem@davemloft.net,
ebiederm@xmission.com, gregkh@linuxfoundation.org,
herbert@gondor.apana.org.au, lucien.xin@gmail.com,
marcelo.leitner@gmail.com, nhorman@tuxdriver.com
Cc: <stable@vger.kernel.org>, <stable-commits@vger.kernel.org>
Subject: Patch "net/sctp: always initialise sctp_ht_iter::start_fail" has been added to the 4.7-stable tree
Date: Wed, 21 Sep 2016 10:05:50 +0200 [thread overview]
Message-ID: <14744451501377@kroah.com> (raw)
This is a note to let you know that I've just added the patch titled
net/sctp: always initialise sctp_ht_iter::start_fail
to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-sctp-always-initialise-sctp_ht_iter-start_fail.patch
and it can be found in the queue-4.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From foo@baz Wed Sep 21 10:05:18 CEST 2016
From: Vegard Nossum <vegard.nossum@oracle.com>
Date: Fri, 12 Aug 2016 09:50:51 +0200
Subject: net/sctp: always initialise sctp_ht_iter::start_fail
From: Vegard Nossum <vegard.nossum@oracle.com>
[ Upstream commit 54236ab09e9696a27baaae693c288920a26e8588 ]
sctp_transport_seq_start() does not currently clear iter->start_fail on
success, but relies on it being zero when it is allocated (by
seq_open_net()).
This can be a problem in the following sequence:
open() // allocates iter (and implicitly sets iter->start_fail = 0)
read()
- iter->start() // fails and sets iter->start_fail = 1
- iter->stop() // doesn't call sctp_transport_walk_stop() (correct)
read() again
- iter->start() // succeeds, but doesn't change iter->start_fail
- iter->stop() // doesn't call sctp_transport_walk_stop() (wrong)
We should initialize sctp_ht_iter::start_fail to zero if ->start()
succeeds, otherwise it's possible that we leave an old value of 1 there,
which will cause ->stop() to not call sctp_transport_walk_stop(), which
causes all sorts of problems like not calling rcu_read_unlock() (and
preempt_enable()), eventually leading to more warnings like this:
BUG: sleeping function called from invalid context at mm/slab.h:388
in_atomic(): 0, irqs_disabled(): 0, pid: 16551, name: trinity-c2
Preemption disabled at:[<ffffffff819bceb6>] rhashtable_walk_start+0x46/0x150
[<ffffffff81149abb>] preempt_count_add+0x1fb/0x280
[<ffffffff83295892>] _raw_spin_lock+0x12/0x40
[<ffffffff819bceb6>] rhashtable_walk_start+0x46/0x150
[<ffffffff82ec665f>] sctp_transport_walk_start+0x2f/0x60
[<ffffffff82edda1d>] sctp_transport_seq_start+0x4d/0x150
[<ffffffff81439e50>] traverse+0x170/0x850
[<ffffffff8143aeec>] seq_read+0x7cc/0x1180
[<ffffffff814f996c>] proc_reg_read+0xbc/0x180
[<ffffffff813d0384>] do_loop_readv_writev+0x134/0x210
[<ffffffff813d2a95>] do_readv_writev+0x565/0x660
[<ffffffff813d6857>] vfs_readv+0x67/0xa0
[<ffffffff813d6c16>] do_preadv+0x126/0x170
[<ffffffff813d710c>] SyS_preadv+0xc/0x10
[<ffffffff8100334c>] do_syscall_64+0x19c/0x410
[<ffffffff83296225>] return_from_SYSCALL_64+0x0/0x6a
[<ffffffffffffffff>] 0xffffffffffffffff
Notice that this is a subtly different stacktrace from the one in commit
5fc382d875 ("net/sctp: terminate rhashtable walk correctly").
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-By: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sctp/proc.c | 1 +
1 file changed, 1 insertion(+)
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -293,6 +293,7 @@ static void *sctp_transport_seq_start(st
return ERR_PTR(err);
}
+ iter->start_fail = 0;
return sctp_transport_get_idx(seq_file_net(seq), &iter->hti, *pos);
}
Patches currently in stable-queue which might be from vegard.nossum@oracle.com are
queue-4.7/net-sctp-always-initialise-sctp_ht_iter-start_fail.patch
queue-4.7/net-irda-handle-iriap_register_lsap-allocation-failure.patch
queue-4.7/tipc-fix-null-pointer-dereference-in-shutdown.patch
reply other threads:[~2016-09-21 8:06 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=14744451501377@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=davem@davemloft.net \
--cc=ebiederm@xmission.com \
--cc=herbert@gondor.apana.org.au \
--cc=lucien.xin@gmail.com \
--cc=marcelo.leitner@gmail.com \
--cc=nhorman@tuxdriver.com \
--cc=stable-commits@vger.kernel.org \
--cc=stable@vger.kernel.org \
--cc=vegard.nossum@oracle.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.