lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20220510130734.778375785@linuxfoundation.org>
Date:   Tue, 10 May 2022 15:08:02 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Mikulas Patocka <mpatocka@...hat.com>,
        Mike Snitzer <snitzer@...hat.com>,
        Mike Snitzer <snitzer@...nel.org>
Subject: [PATCH 4.14 76/78] dm: interlock pending dm_io and dm_wait_for_bios_completion

From: Mike Snitzer <snitzer@...hat.com>

commit 9f6dc633761006f974701d4c88da71ab68670749 upstream.

Commit d208b89401e0 ("dm: fix mempool NULL pointer race when
completing IO") didn't go far enough.

When bio_end_io_acct ends the count of in-flight I/Os may reach zero
and the DM device may be suspended. There is a possibility that the
suspend races with dm_stats_account_io.

Fix this by adding percpu "pending_io" counters to track outstanding
dm_io. Move kicking of suspend queue to dm_io_dec_pending(). Also,
rename md_in_flight_bios() to dm_in_flight_bios() and update it to
iterate all pending_io counters.

Fixes: d208b89401e0 ("dm: fix mempool NULL pointer race when completing IO")
Cc: stable@...r.kernel.org
Co-developed-by: Mikulas Patocka <mpatocka@...hat.com>
Signed-off-by: Mikulas Patocka <mpatocka@...hat.com>
Signed-off-by: Mike Snitzer <snitzer@...hat.com>
Signed-off-by: Mikulas Patocka <mpatocka@...hat.com>
Reviewed-by: Mike Snitzer <snitzer@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/md/dm.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2230,6 +2230,8 @@ static int dm_wait_for_completion(struct
 	}
 	finish_wait(&md->wait, &wait);
 
+	smp_rmb(); /* paired with atomic_dec_return in end_io_acct */
+
 	return r;
 }
 


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ