From 25e9f88c7e3cc35f5e3d3db199660d28a15df639 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin Date: Thu, 30 Sep 2021 20:50:28 +0300 Subject: phy: mdio: fix memory leak [ Upstream commit ca6e11c337daf7925ff8a2aac8e84490a8691905 ] Syzbot reported memory leak in MDIO bus interface, the problem was in wrong state logic. MDIOBUS_ALLOCATED indicates 2 states: 1. Bus is only allocated 2. Bus allocated and __mdiobus_register() fails, but device_register() was called In case of device_register() has been called we should call put_device() to correctly free the memory allocated for this device, but mdiobus_free() calls just kfree(dev) in case of MDIOBUS_ALLOCATED state To avoid this behaviour we need to set bus->state to MDIOBUS_UNREGISTERED _before_ calling device_register(), because put_device() should be called even in case of device_register() failure. Link: https://lore.kernel.org/netdev/YVMRWNDZDUOvQjHL@shell.armlinux.org.uk/ Fixes: 46abc02175b3 ("phylib: give mdio buses a device tree presence") Reported-and-tested-by: syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com Reviewed-by: Dan Carpenter Signed-off-by: Pavel Skripkin Link: https://lore.kernel.org/r/eceae1429fbf8fa5c73dd2a0d39d525aa905074d.1633024062.git.paskripkin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/phy/mdio_bus.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/net/phy/mdio_bus.c') diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 5ea86fd57ae6..4066fb5a935a 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -264,6 +264,13 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) bus->dev.groups = NULL; dev_set_name(&bus->dev, "%s", bus->id); + /* We need to set state to MDIOBUS_UNREGISTERED to correctly release + * the device in mdiobus_free() + * + * State will be updated later in this function in case of success + */ + bus->state = MDIOBUS_UNREGISTERED; + err = device_register(&bus->dev); if (err) { pr_err("mii_bus %s failed to register\n", bus->id); -- cgit v1.2.3 From fd2400dd4f1b8bd7a309b1b424d9e0d188151b01 Mon Sep 17 00:00:00 2001 From: Yanfei Xu Date: Sun, 26 Sep 2021 12:53:13 +0800 Subject: net: mdiobus: Fix memory leak in __mdiobus_register commit ab609f25d19858513919369ff3d9a63c02cd9e2e upstream. Once device_register() failed, we should call put_device() to decrement reference count for cleanup. Or it will cause memory leak. BUG: memory leak unreferenced object 0xffff888114032e00 (size 256): comm "kworker/1:3", pid 2960, jiffies 4294943572 (age 15.920s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 2e 03 14 81 88 ff ff ................ 08 2e 03 14 81 88 ff ff 90 76 65 82 ff ff ff ff .........ve..... backtrace: [] kmalloc include/linux/slab.h:591 [inline] [] kzalloc include/linux/slab.h:721 [inline] [] device_private_init drivers/base/core.c:3203 [inline] [] device_add+0x89b/0xdf0 drivers/base/core.c:3253 [] __mdiobus_register+0xc3/0x450 drivers/net/phy/mdio_bus.c:537 [] __devm_mdiobus_register+0x75/0xf0 drivers/net/phy/mdio_devres.c:87 [] ax88772_init_mdio drivers/net/usb/asix_devices.c:676 [inline] [] ax88772_bind+0x330/0x480 drivers/net/usb/asix_devices.c:786 [] usbnet_probe+0x3ff/0xdf0 drivers/net/usb/usbnet.c:1745 [] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396 [] call_driver_probe drivers/base/dd.c:517 [inline] [] really_probe.part.0+0xe7/0x380 drivers/base/dd.c:596 [] really_probe drivers/base/dd.c:558 [inline] [] __driver_probe_device+0x10c/0x1e0 drivers/base/dd.c:751 [] driver_probe_device+0x2a/0x120 drivers/base/dd.c:781 [] __device_attach_driver+0xf6/0x140 drivers/base/dd.c:898 [] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:427 [] __device_attach+0x122/0x260 drivers/base/dd.c:969 [] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:487 [] device_add+0x5fb/0xdf0 drivers/base/core.c:3359 [] usb_set_configuration+0x9d9/0xb90 drivers/usb/core/message.c:2170 [] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238 BUG: memory leak unreferenced object 0xffff888116f06900 (size 32): comm "kworker/0:2", pid 2670, jiffies 4294944448 (age 7.160s) hex dump (first 32 bytes): 75 73 62 2d 30 30 31 3a 30 30 33 00 00 00 00 00 usb-001:003..... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kstrdup+0x36/0x70 mm/util.c:60 [] kstrdup_const+0x53/0x80 mm/util.c:83 [] kvasprintf_const+0xc2/0x110 lib/kasprintf.c:48 [] kobject_set_name_vargs+0x3b/0xe0 lib/kobject.c:289 [] dev_set_name+0x63/0x90 drivers/base/core.c:3147 [] __mdiobus_register+0xbb/0x450 drivers/net/phy/mdio_bus.c:535 [] __devm_mdiobus_register+0x75/0xf0 drivers/net/phy/mdio_devres.c:87 [] ax88772_init_mdio drivers/net/usb/asix_devices.c:676 [inline] [] ax88772_bind+0x330/0x480 drivers/net/usb/asix_devices.c:786 [] usbnet_probe+0x3ff/0xdf0 drivers/net/usb/usbnet.c:1745 [] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396 [] call_driver_probe drivers/base/dd.c:517 [inline] [] really_probe.part.0+0xe7/0x380 drivers/base/dd.c:596 [] really_probe drivers/base/dd.c:558 [inline] [] __driver_probe_device+0x10c/0x1e0 drivers/base/dd.c:751 [] driver_probe_device+0x2a/0x120 drivers/base/dd.c:781 [] __device_attach_driver+0xf6/0x140 drivers/base/dd.c:898 [] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:427 [] __device_attach+0x122/0x260 drivers/base/dd.c:969 Reported-by: syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com Signed-off-by: Yanfei Xu Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/phy/mdio_bus.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/net/phy/mdio_bus.c') diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 4066fb5a935a..d621cf07f3e0 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -274,6 +274,7 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) err = device_register(&bus->dev); if (err) { pr_err("mii_bus %s failed to register\n", bus->id); + put_device(&bus->dev); return -EINVAL; } -- cgit v1.2.3 From b89f4537d7fdbd0bafb6d8a66a484e0bc99871a4 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin Date: Thu, 30 Sep 2021 20:49:42 +0300 Subject: Revert "net: mdiobus: Fix memory leak in __mdiobus_register" commit 10eff1f5788b6ffac212c254e2f3666219576889 upstream. This reverts commit ab609f25d19858513919369ff3d9a63c02cd9e2e. This patch is correct in the sense that we _should_ call device_put() in case of device_register() failure, but the problem in this code is more vast. We need to set bus->state to UNMDIOBUS_REGISTERED before calling device_register() to correctly release the device in mdiobus_free(). This patch prevents us from doing it, since in case of device_register() failure put_device() will be called 2 times and it will cause UAF or something else. Also, Reported-by: tag in revered commit was wrong, since syzbot reported different leak in same function. Link: https://lore.kernel.org/netdev/20210928092657.GI2048@kadam/ Acked-by: Yanfei Xu Signed-off-by: Pavel Skripkin Link: https://lore.kernel.org/r/f12fb1faa4eccf0f355788225335eb4309ff2599.1633024062.git.paskripkin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/phy/mdio_bus.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/net/phy/mdio_bus.c') diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index d621cf07f3e0..4066fb5a935a 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -274,7 +274,6 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) err = device_register(&bus->dev); if (err) { pr_err("mii_bus %s failed to register\n", bus->id); - put_device(&bus->dev); return -EINVAL; } -- cgit v1.2.3