dmaengine: idxd: Fix a possible NULL pointer dereference

'device_driver_attach()' dereferences its first argument (i.e. 'alt_drv')
so it must not be NULL.
Simplify the error handling logic about NULL 'alt_drv' in order to be
more robust and future-proof.

Fixes: 568b212646 ("dmaengine: idxd: fix uninit var for alt_drv")
Fixes: 6e7f3ee97b ("dmaengine: idxd: move dsa_drv support to compatible mode")

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/77f0dc4f3966591d1f0cffb614a94085f8895a85.1627560174.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Christophe JAILLET 2021-07-29 14:04:01 +02:00 committed by Vinod Koul
parent ffa179ae2a
commit e9c5b0b53c

View File

@ -45,23 +45,16 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, size_t cou
idxd_dev = confdev_to_idxd_dev(dev);
if (is_idxd_dev(idxd_dev)) {
alt_drv = driver_find("idxd", bus);
if (!alt_drv)
return -ENODEV;
} else if (is_idxd_wq_dev(idxd_dev)) {
struct idxd_wq *wq = confdev_to_wq(dev);
if (is_idxd_wq_kernel(wq)) {
if (is_idxd_wq_kernel(wq))
alt_drv = driver_find("dmaengine", bus);
if (!alt_drv)
return -ENODEV;
} else if (is_idxd_wq_user(wq)) {
else if (is_idxd_wq_user(wq))
alt_drv = driver_find("user", bus);
if (!alt_drv)
return -ENODEV;
} else {
return -ENODEV;
}
}
if (!alt_drv)
return -ENODEV;
rc = device_driver_attach(alt_drv, dev);
if (rc < 0)