linux-kernel - Re: [PATCH] [RESEND] qla2xxx: fix potential deadlock on ha->hardware

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: <CC98FFD9.ECEC%saurav.kashyap@qlogic.com>
Date:	Mon, 8 Oct 2012 11:43:42 -0500
From:	Saurav Kashyap <saurav.kashyap@...gic.com>
To:	Jiri Kosina <jkosina@...e.cz>,
	"James E.J. Bottomley" <JBottomley@...allels.com>,
	Dept-Eng Linux Driver <Linux-Driver@...gic.com>,
	Andrew Vasquez <andrew.vasquez@...gic.com>
CC:	"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Nicholas Bellinger <nab@...ux-iscsi.org>,
	"Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>
Subject: Re: [PATCH] [RESEND] qla2xxx: fix potential deadlock on
 ha->hardware_lock

Acked-by: Saurav Kashyap <saurav.kashyap@...gic.com>

Thanks,
~Saurav


>Lockdep reports:
>
>=== [ cut here ] ===
> =========================================================
> [ INFO: possible irq lock inversion dependency detected ]
> 3.6.0-0.0.0.28.36b5ec9-default #1 Not tainted
> ---------------------------------------------------------
> qla2xxx_1_dpc/368 just changed the state of lock:
>  (&(&ha->vport_slock)->rlock){+.....}, at: [<ffffffffa009b377>]
>qla2x00_configure_hba+0x197/0x3c0 [qla2xxx]
> but this lock was taken by another, HARDIRQ-safe lock in the past:
>  (&(&ha->hardware_lock)->rlock){-.....}
>
>and interrupts could create inverse lock ordering between them.
>
>other info that might help us debug this:
> Possible interrupt unsafe locking scenario:
>
>       CPU0                    CPU1
>       ----                    ----
>  lock(&(&ha->vport_slock)->rlock);
>                               local_irq_disable();
>                               lock(&(&ha->hardware_lock)->rlock);
>                               lock(&(&ha->vport_slock)->rlock);
>  <Interrupt>
>    lock(&(&ha->hardware_lock)->rlock);
>=== [ cut here ] ===
>
>Fix the potential deadlock by disabling IRQs while holding
>ha->vport_slock.
>
>Reported-and-tested-by: Srivatsa S. Bhat
><srivatsa.bhat@...ux.vnet.ibm.com>
>Signed-off-by: Jiri Kosina <jkosina@...e.cz>
>---
> drivers/scsi/qla2xxx/qla_init.c |    5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/scsi/qla2xxx/qla_init.c
>b/drivers/scsi/qla2xxx/qla_init.c
>index 799a58b..48fca47 100644
>--- a/drivers/scsi/qla2xxx/qla_init.c
>+++ b/drivers/scsi/qla2xxx/qla_init.c
>@@ -2080,6 +2080,7 @@ qla2x00_configure_hba(scsi_qla_host_t *vha)
>       uint8_t       domain;
>       char            connect_type[22];
>       struct qla_hw_data *ha = vha->hw;
>+      unsigned long flags;
>
>       /* Get host addresses. */
>       rval = qla2x00_get_adapter_id(vha,
>@@ -2154,9 +2155,9 @@ qla2x00_configure_hba(scsi_qla_host_t *vha)
>       vha->d_id.b.area = area;
>       vha->d_id.b.al_pa = al_pa;
>
>-      spin_lock(&ha->vport_slock);
>+      spin_lock_irqsave(&ha->vport_slock, flags);
>       qlt_update_vp_map(vha, SET_AL_PA);
>-      spin_unlock(&ha->vport_slock);
>+      spin_unlock_irqrestore(&ha->vport_slock, flags);
>
>       if (!vha->flags.init_done)
>               ql_log(ql_log_info, vha, 0x2010,
>
>--
>Jiri Kosina
>SUSE Labs
>--
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majordomo@...r.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>


This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/