| Message ID | 20190319213613.48888-1-wanghai26@huawei.com |
|---|---|
| State | Superseded |
| Delegated to: | David Miller |
| Headers | show |
| Series | [v2] net-sysfs: Fix memory leak in netdev_register_kobject | expand |
On Tue, Mar 19, 2019 at 05:36:13PM -0400, Wang Hai wrote: > When registering struct net_device, it will call > register_netdevice -> > netdev_register_kobject -> > dev_set_name(dev, "%s", ndev->name) > device_add(dev) > register_queue_kobjects(ndev) > > - Improve the description of the cause of the bug, no code changes. See my previous message. NAK for this.
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 4ff661f..f0e53dc 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1745,17 +1745,22 @@ int netdev_register_kobject(struct net_device *ndev) error = device_add(dev); if (error) - return error; + goto device_add_error; error = register_queue_kobjects(ndev); - if (error) { - device_del(dev); - return error; - } + if (error) + goto register_error; pm_runtime_set_memalloc_noio(dev, true); +out: return error; + +register_error: + device_del(dev); +device_add_error: + kfree_const(dev->kobj.name); + goto out; } int netdev_class_create_file_ns(const struct class_attribute *class_attr,
When registering struct net_device, it will call register_netdevice -> netdev_register_kobject -> dev_set_name(dev, "%s", ndev->name) device_add(dev) register_queue_kobjects(ndev) In netdev_register_kobject(), if dev->kobj.name was successfully created in dev_set_name(), but 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 (&ndev->dev)->kobj.name will not be freed, 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 <hulkci@huawei.com> Fixes: 1fa5ae857bb1 ("driver core: get rid of struct device's bus_id string array") Signed-off-by: Wang Hai <wanghai26@huawei.com> --- v1 -> v2: - Fix the commit id of Fixes - Improve the description of the cause of the bug, no code changes. --- net/core/net-sysfs.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)