From a3eb7fbb41eb8d6e22d491741b8c5d5aa6cb069a Mon Sep 17 00:00:00 2001 From: Alexey Khoroshilov Date: Mon, 10 Feb 2014 14:25:35 -0800 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/message/i2o/i2o_config.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/message/i2o/i2o_config.c b/drivers/message/i2o/i2o_config.c index a60c188c2bd9..04bd3b6de401 100644 --- a/drivers/message/i2o/i2o_config.c +++ b/drivers/message/i2o/i2o_config.c @@ -754,19 +754,19 @@ static long i2o_cfg_compat_ioctl(struct file *file, unsigned cmd, 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; } -- 2.30.2