From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
syzbot+acdeb633f6211ccdf886@syzkaller.appspotmail.com,
Ilya Dryomov <idryomov@gmail.com>,
Myungho Jung <mhjungk@gmail.com>
Subject: [PATCH 4.9 21/24] libceph: avoid KEEPALIVE_PENDING races in ceph_con_keepalive()
Date: Wed, 13 Feb 2019 19:38:18 +0100 [thread overview]
Message-ID: <20190213183649.232203318@linuxfoundation.org> (raw)
In-Reply-To: <20190213183647.333441569@linuxfoundation.org>
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ilya Dryomov <idryomov@gmail.com>
commit 4aac9228d16458cedcfd90c7fb37211cf3653ac3 upstream.
con_fault() can transition the connection into STANDBY right after
ceph_con_keepalive() clears STANDBY in clear_standby():
libceph user thread ceph-msgr worker
ceph_con_keepalive()
mutex_lock(&con->mutex)
clear_standby(con)
mutex_unlock(&con->mutex)
mutex_lock(&con->mutex)
con_fault()
...
if KEEPALIVE_PENDING isn't set
set state to STANDBY
...
mutex_unlock(&con->mutex)
set KEEPALIVE_PENDING
set WRITE_PENDING
This triggers warnings in clear_standby() when either ceph_con_send()
or ceph_con_keepalive() get to clearing STANDBY next time.
I don't see a reason to condition queue_con() call on the previous
value of KEEPALIVE_PENDING, so move the setting of KEEPALIVE_PENDING
into the critical section -- unlike WRITE_PENDING, KEEPALIVE_PENDING
could have been a non-atomic flag.
Reported-by: syzbot+acdeb633f6211ccdf886@syzkaller.appspotmail.com
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Myungho Jung <mhjungk@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ceph/messenger.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -3186,9 +3186,10 @@ void ceph_con_keepalive(struct ceph_conn
dout("con_keepalive %p\n", con);
mutex_lock(&con->mutex);
clear_standby(con);
+ con_flag_set(con, CON_FLAG_KEEPALIVE_PENDING);
mutex_unlock(&con->mutex);
- if (con_flag_test_and_set(con, CON_FLAG_KEEPALIVE_PENDING) == 0 &&
- con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
+
+ if (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
queue_con(con);
}
EXPORT_SYMBOL(ceph_con_keepalive);
next prev parent reply other threads:[~2019-02-13 18:56 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-13 18:37 [PATCH 4.9 00/24] 4.9.157-stable review Greg Kroah-Hartman
2019-02-13 18:37 ` [PATCH 4.9 01/24] mtd: rawnand: gpmi: fix MX28 bus master lockup problem Greg Kroah-Hartman
2019-02-13 18:37 ` [PATCH 4.9 02/24] iio: chemical: atlas-ph-sensor: correct IIO_TEMP values to millicelsius Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 03/24] signal: Always notice exiting tasks Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 04/24] signal: Better detection of synchronous signals Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 05/24] misc: vexpress: Off by one in vexpress_syscfg_exec() Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 06/24] samples: mei: use /dev/mei0 instead of /dev/mei Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 07/24] debugfs: fix debugfs_rename parameter checking Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 08/24] mips: cm: reprime error cause Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 09/24] MIPS: OCTEON: dont set octeon_dma_bar_type if PCI is disabled Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 10/24] MIPS: VDSO: Include $(ccflags-vdso) in o32,n32 .lds builds Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 11/24] ARM: iop32x/n2100: fix PCI IRQ mapping Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 12/24] ARM: tango: Improve ARCH_MULTIPLATFORM compatibility Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 13/24] mac80211: ensure that mgmt tx skbs have tailroom for encryption Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 14/24] drm/modes: Prevent division by zero htotal Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 15/24] drm/vmwgfx: Fix setting of dma masks Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 16/24] drm/vmwgfx: Return error code from vmw_execbuf_copy_fence_user Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 17/24] nfsd4: fix cached replies to solo SEQUENCE compounds Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 18/24] nfsd4: catch some false session retries Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 19/24] HID: debug: fix the ring buffer implementation Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 20/24] Revert "cifs: In Kconfig CONFIG_CIFS_POSIX needs depends on legacy (insecure cifs)" Greg Kroah-Hartman
2019-02-13 18:38 ` Greg Kroah-Hartman [this message]
2019-02-13 18:38 ` [PATCH 4.9 22/24] xfrm: refine validation of template and selector families Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 23/24] batman-adv: Avoid WARN on net_device without parent in netns Greg Kroah-Hartman
2019-02-13 18:38 ` [PATCH 4.9 24/24] batman-adv: Force mac header to start of data on xmit Greg Kroah-Hartman
2019-02-14 3:39 ` [PATCH 4.9 00/24] 4.9.157-stable review kernelci.org bot
2019-02-14 10:04 ` Jon Hunter
2019-02-14 16:30 ` Dan Rue
2019-02-14 19:16 ` Guenter Roeck
2019-02-14 22:22 ` shuah
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=20190213183649.232203318@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=idryomov@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mhjungk@gmail.com \
--cc=stable@vger.kernel.org \
--cc=syzbot+acdeb633f6211ccdf886@syzkaller.appspotmail.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).