Messages in this thread Patch in this message | | | From | Alexey Khoroshilov <> | Subject | [RESEND PATCH] [SCSI] mpt2sas: fix double mutex lock in NON_BLOCKING state | Date | Fri, 24 Aug 2012 21:14:38 +0400 |
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If state is NON_BLOCKING and mutex_trylock is succeed, the control flow goes to mutex_lock_interruptible() that is a deadlock.
Found by Linux Driver Verification project (linuxtesting.org).
Acked-by: "Nandigama, Nagalakshmi" <Nagalakshmi.Nandigama@lsi.com> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> --- drivers/scsi/mpt2sas/mpt2sas_ctl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c b/drivers/scsi/mpt2sas/mpt2sas_ctl.c index 49bdd2d..d29ea56 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c +++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c @@ -2181,8 +2181,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg, return -EAGAIN; state = (file->f_flags & O_NONBLOCK) ? NON_BLOCKING : BLOCKING; - if (state == NON_BLOCKING && !mutex_trylock(&ioc->ctl_cmds.mutex)) - return -EAGAIN; + if (state == NON_BLOCKING) { + if (!mutex_trylock(&ioc->ctl_cmds.mutex)) + return -EAGAIN; + } else if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex)) return -ERESTARTSYS; -- 1.7.9.5
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