From e9c5b0b53ccca81dd0a35c62309e243a57c7959d Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Thu, 29 Jul 2021 14:04:01 +0200 Subject: 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: 568b2126466f ("dmaengine: idxd: fix uninit var for alt_drv") Fixes: 6e7f3ee97bbe ("dmaengine: idxd: move dsa_drv support to compatible mode") Signed-off-by: Christophe JAILLET Acked-by: Dave Jiang Link: https://lore.kernel.org/r/77f0dc4f3966591d1f0cffb614a94085f8895a85.1627560174.git.christophe.jaillet@wanadoo.fr Signed-off-by: Vinod Koul --- drivers/dma/idxd/compat.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) (limited to 'drivers/dma') diff --git a/drivers/dma/idxd/compat.c b/drivers/dma/idxd/compat.c index d7616c240dcd..3df21615f888 100644 --- a/drivers/dma/idxd/compat.c +++ b/drivers/dma/idxd/compat.c @@ -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) -- cgit v1.2.3