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@xxxxxxx>
Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
---
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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