From a3e23f719f5c4a38ffb3d30c8d7632a4ed8ccd9e Mon Sep 17 00:00:00 2001 From: YueHaibing Date: Tue, 19 Mar 2019 10:16:53 +0800 Subject: net-sysfs: call dev_hold if kobject_init_and_add success In netdev_queue_add_kobject and rx_queue_add_kobject, if sysfs_create_group failed, kobject_put will call netdev_queue_release to decrease dev refcont, however dev_hold has not be called. So we will see this while unregistering dev: unregister_netdevice: waiting for bcsh0 to become free. Usage count = -1 Reported-by: Hulk Robot Fixes: d0d668371679 ("net: don't decrement kobj reference count on init failure") Signed-off-by: YueHaibing Signed-off-by: David S. Miller --- net/core/net-sysfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/core/net-sysfs.c') diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 4ff661f6f989..8f8b7b6c2945 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -928,6 +928,8 @@ static int rx_queue_add_kobject(struct net_device *dev, int index) if (error) return error; + dev_hold(queue->dev); + if (dev->sysfs_rx_queue_group) { error = sysfs_create_group(kobj, dev->sysfs_rx_queue_group); if (error) { @@ -937,7 +939,6 @@ static int rx_queue_add_kobject(struct net_device *dev, int index) } kobject_uevent(kobj, KOBJ_ADD); - dev_hold(queue->dev); return error; } @@ -1464,6 +1465,8 @@ static int netdev_queue_add_kobject(struct net_device *dev, int index) if (error) return error; + dev_hold(queue->dev); + #ifdef CONFIG_BQL error = sysfs_create_group(kobj, &dql_group); if (error) { @@ -1473,7 +1476,6 @@ static int netdev_queue_add_kobject(struct net_device *dev, int index) #endif kobject_uevent(kobj, KOBJ_ADD); - dev_hold(queue->dev); return 0; } -- cgit From 6b70fc94afd165342876e53fc4b2f7d085009945 Mon Sep 17 00:00:00 2001 From: Wang Hai Date: Wed, 20 Mar 2019 14:25:05 -0400 Subject: net-sysfs: Fix memory leak in netdev_register_kobject When registering struct net_device, it will call register_netdevice -> netdev_register_kobject -> device_initialize(dev); dev_set_name(dev, "%s", ndev->name) device_add(dev) register_queue_kobjects(ndev) In netdev_register_kobject(), if device_add(dev) or register_queue_kobjects(ndev) failed. Register_netdevice() will return error, causing netdev_freemem(ndev) to be called to free net_device, however put_device(&dev->dev)->..-> kobject_cleanup() won't be called, resulting in a memory leak. syzkaller report this: BUG: memory leak unreferenced object 0xffff8881f4fad168 (size 8): comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s) hex dump (first 8 bytes): 77 70 61 6e 30 00 ff ff wpan0... backtrace: [<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73 [<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48 [<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281 [<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915 [<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727 [<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711 [<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154] [<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154] [<00000000e4b3df51>] 0xffffffffc1500e0e [<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614 [<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509 [<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671 [<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945 [<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022 [<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304 [<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645 Reported-by: Hulk Robot Fixes: 1fa5ae857bb1 ("driver core: get rid of struct device's bus_id string array") Signed-off-by: Wang Hai Reviewed-by: Andy Shevchenko Reviewed-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/core/net-sysfs.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'net/core/net-sysfs.c') diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 8f8b7b6c2945..f8f94303a1f5 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1747,16 +1747,20 @@ int netdev_register_kobject(struct net_device *ndev) error = device_add(dev); if (error) - return error; + goto error_put_device; error = register_queue_kobjects(ndev); - if (error) { - device_del(dev); - return error; - } + if (error) + goto error_device_del; pm_runtime_set_memalloc_noio(dev, true); + return 0; + +error_device_del: + device_del(dev); +error_put_device: + put_device(dev); return error; } -- cgit