drivers/message/i2o/i2o_config.c: fix deadlock in compat_ioctl(I2OGETIOPS)
i2o_cfg_compat_ioctl(I2OGETIOPS) locks i2o_cfg_mutex and then calls
i2o_cfg_ioctl(I2OGETIOPS) that locks i2o_cfg_mutex as well. A deadlock
is guaranteed.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/message/i2o/i2o_config.c b/drivers/message/i2o/i2o_config.c
index a60c188..04bd3b6 100644
--- a/drivers/message/i2o/i2o_config.c
+++ b/drivers/message/i2o/i2o_config.c
@@ -754,19 +754,19 @@
unsigned long arg)
{
int ret;
- mutex_lock(&i2o_cfg_mutex);
switch (cmd) {
case I2OGETIOPS:
ret = i2o_cfg_ioctl(file, cmd, arg);
break;
case I2OPASSTHRU32:
+ mutex_lock(&i2o_cfg_mutex);
ret = i2o_cfg_passthru32(file, cmd, arg);
+ mutex_unlock(&i2o_cfg_mutex);
break;
default:
ret = -ENOIOCTLCMD;
break;
}
- mutex_unlock(&i2o_cfg_mutex);
return ret;
}