| Message ID | d7710b468c6c1b9cf3b3fe2fc986118a2cd2639a.1506510873.git.arvind.yadav.cs@gmail.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [RFT] lan78xx: FIX use-after-free in lan78xx_write_reg | expand |
On Wed, Sep 27, 2017 at 1:18 PM, Arvind Yadav <arvind.yadav.cs@gmail.com> wrote: > We are not releasing 'buf' memory on failure or disconnect a device. > > Adding 'u8 *buf' as part of 'lan78xx_net' structure to make proper > handle for 'buf'. > Now releasing 'buf' memory on failure. It's allocate first in > lan78xx_probe() and it should be freed last in lan78xx_disconnect(). > > Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Hi Arvind, I've tried your patch and still see a crash. Thanks! lan78xx 1-1:90.0 (unnamed net_device) (uninitialized): can't register MDIO bus lan78xx: probe of 1-1:90.0 failed with error -5 usb 1-1: USB disconnect, device number 2 ================================================================== BUG: KASAN: use-after-free in lan78xx_write_reg.isra.21+0x1a8/0x1b0 Read of size 8 at addr ffff880063dfac40 by task kworker/1:1/1152 CPU: 1 PID: 1152 Comm: kworker/1:1 Not tainted 4.14.0-rc2-42660-g24b7bd59eec0-dirty #274 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: events lan78xx_deferred_multicast_write Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 print_address_description+0x78/0x280 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 kasan_report+0x23d/0x350 mm/kasan/report.c:409 __asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:430 lan78xx_write_reg.isra.21+0x1a8/0x1b0 drivers/net/usb/lan78xx.c:459 lan78xx_deferred_multicast_write+0x10d/0x1a0 drivers/net/usb/lan78xx.c:1043 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Allocated by task 1848: save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 __kmalloc_node+0x192/0x480 mm/slub.c:3827 kmalloc_node ./include/linux/slab.h:535 kvmalloc_node+0x69/0xd0 mm/util.c:397 kvmalloc ./include/linux/mm.h:529 kvzalloc ./include/linux/mm.h:537 alloc_netdev_mqs+0x173/0xea0 net/core/dev.c:8023 alloc_etherdev_mqs+0x38/0x40 net/ethernet/eth.c:391 lan78xx_probe+0x13a/0x3020 drivers/net/usb/lan78xx.c:3545 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Freed by task 1848: save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524 slab_free_hook mm/slub.c:1390 slab_free_freelist_hook mm/slub.c:1412 slab_free mm/slub.c:2988 kfree+0xf6/0x2f0 mm/slub.c:3919 kvfree+0x3b/0x60 mm/util.c:416 netdev_freemem net/core/dev.c:7975 free_netdev+0x304/0x3c0 net/core/dev.c:8137 lan78xx_probe+0x21a4/0x3020 drivers/net/usb/lan78xx.c:3649 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 The buggy address belongs to the object at ffff880063dfa100 which belongs to the cache kmalloc-8192 of size 8192 The buggy address is located 2880 bytes inside of 8192-byte region [ffff880063dfa100, ffff880063dfc100) The buggy address belongs to the page: page:ffffea00018f7e00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x100000000008100(slab|head) raw: 0100000000008100 0000000000000000 0000000000000000 0000000100030003 raw: ffffea0001afd800 0000000300000003 ffff88006c402a80 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880063dfab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880063dfab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880063dfac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880063dfac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880063dfad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== > --- > drivers/net/usb/lan78xx.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c > index b99a7fb..e653982 100644 > --- a/drivers/net/usb/lan78xx.c > +++ b/drivers/net/usb/lan78xx.c > @@ -402,6 +402,7 @@ struct lan78xx_net { > struct statstage stats; > > struct irq_domain_data domain_data; > + u8 *buf; > }; > > /* define external phy id */ > @@ -3470,6 +3471,9 @@ static void lan78xx_disconnect(struct usb_interface *intf) > > usb_scuttle_anchored_urbs(&dev->deferred); > > + kfree(dev->buf); > + dev->buf = NULL; > + > lan78xx_unbind(dev, intf); > > usb_kill_urb(dev->urb_intr); > @@ -3520,7 +3524,6 @@ static int lan78xx_probe(struct usb_interface *intf, > int ret; > unsigned maxp; > unsigned period; > - u8 *buf = NULL; > > udev = interface_to_usbdev(intf); > udev = usb_get_dev(udev); > @@ -3588,16 +3591,15 @@ static int lan78xx_probe(struct usb_interface *intf, > period = dev->ep_intr->desc.bInterval; > > maxp = usb_maxpacket(dev->udev, dev->pipe_intr, 0); > - buf = kmalloc(maxp, GFP_KERNEL); > - if (buf) { > + dev->buf = kmalloc(maxp, GFP_KERNEL); > + if (dev->buf) { > dev->urb_intr = usb_alloc_urb(0, GFP_KERNEL); > if (!dev->urb_intr) { > ret = -ENOMEM; > - kfree(buf); > goto out3; > } else { > usb_fill_int_urb(dev->urb_intr, dev->udev, > - dev->pipe_intr, buf, maxp, > + dev->pipe_intr, dev->buf, maxp, > intr_complete, dev, period); > } > } > @@ -3626,6 +3628,8 @@ static int lan78xx_probe(struct usb_interface *intf, > return 0; > > out3: > + kfree(dev->buf); > + dev->buf = NULL; > lan78xx_unbind(dev, intf); > out2: > free_netdev(netdev); > -- > 1.9.1 >
On Wed, Sep 27, 2017 at 2:06 PM, Andrey Konovalov <andreyknvl@google.com> wrote: > On Wed, Sep 27, 2017 at 1:18 PM, Arvind Yadav <arvind.yadav.cs@gmail.com> wrote: >> We are not releasing 'buf' memory on failure or disconnect a device. >> >> Adding 'u8 *buf' as part of 'lan78xx_net' structure to make proper >> handle for 'buf'. >> Now releasing 'buf' memory on failure. It's allocate first in >> lan78xx_probe() and it should be freed last in lan78xx_disconnect(). >> >> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> > > Hi Arvind, > > I've tried your patch and still see a crash. > > Thanks! > > lan78xx 1-1:90.0 (unnamed net_device) (uninitialized): can't register MDIO bus > lan78xx: probe of 1-1:90.0 failed with error -5 > usb 1-1: USB disconnect, device number 2 > ================================================================== > BUG: KASAN: use-after-free in lan78xx_write_reg.isra.21+0x1a8/0x1b0 > Read of size 8 at addr ffff880063dfac40 by task kworker/1:1/1152 It seems that the bug is caused by the fact that the lan78xx_deferred_multicast_write() work is not shut down on lan78xx_probe() failure. > > CPU: 1 PID: 1152 Comm: kworker/1:1 Not tainted > 4.14.0-rc2-42660-g24b7bd59eec0-dirty #274 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > Workqueue: events lan78xx_deferred_multicast_write > Call Trace: > __dump_stack lib/dump_stack.c:16 > dump_stack+0x292/0x395 lib/dump_stack.c:52 > print_address_description+0x78/0x280 mm/kasan/report.c:252 > kasan_report_error mm/kasan/report.c:351 > kasan_report+0x23d/0x350 mm/kasan/report.c:409 > __asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:430 > lan78xx_write_reg.isra.21+0x1a8/0x1b0 drivers/net/usb/lan78xx.c:459 > lan78xx_deferred_multicast_write+0x10d/0x1a0 drivers/net/usb/lan78xx.c:1043 > process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 > worker_thread+0x221/0x1850 kernel/workqueue.c:2253 > kthread+0x3a1/0x470 kernel/kthread.c:231 > ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 > > Allocated by task 1848: > save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 > __kmalloc_node+0x192/0x480 mm/slub.c:3827 > kmalloc_node ./include/linux/slab.h:535 > kvmalloc_node+0x69/0xd0 mm/util.c:397 > kvmalloc ./include/linux/mm.h:529 > kvzalloc ./include/linux/mm.h:537 > alloc_netdev_mqs+0x173/0xea0 net/core/dev.c:8023 > alloc_etherdev_mqs+0x38/0x40 net/ethernet/eth.c:391 > lan78xx_probe+0x13a/0x3020 drivers/net/usb/lan78xx.c:3545 > usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 > really_probe drivers/base/dd.c:413 > driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 > __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 > bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 > __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 > device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 > bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 > device_add+0xd0b/0x1660 drivers/base/core.c:1835 > usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 > generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 > usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 > really_probe drivers/base/dd.c:413 > driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 > __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 > bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 > __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 > device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 > bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 > device_add+0xd0b/0x1660 drivers/base/core.c:1835 > usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 > hub_port_connect drivers/usb/core/hub.c:4903 > hub_port_connect_change drivers/usb/core/hub.c:5009 > port_event drivers/usb/core/hub.c:5115 > hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 > process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 > worker_thread+0x221/0x1850 kernel/workqueue.c:2253 > kthread+0x3a1/0x470 kernel/kthread.c:231 > ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 > > Freed by task 1848: > save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 > kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524 > slab_free_hook mm/slub.c:1390 > slab_free_freelist_hook mm/slub.c:1412 > slab_free mm/slub.c:2988 > kfree+0xf6/0x2f0 mm/slub.c:3919 > kvfree+0x3b/0x60 mm/util.c:416 > netdev_freemem net/core/dev.c:7975 > free_netdev+0x304/0x3c0 net/core/dev.c:8137 > lan78xx_probe+0x21a4/0x3020 drivers/net/usb/lan78xx.c:3649 > usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 > really_probe drivers/base/dd.c:413 > driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 > __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 > bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 > __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 > device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 > bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 > device_add+0xd0b/0x1660 drivers/base/core.c:1835 > usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 > generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 > usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 > really_probe drivers/base/dd.c:413 > driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 > __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 > bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 > __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 > device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 > bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 > device_add+0xd0b/0x1660 drivers/base/core.c:1835 > usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 > hub_port_connect drivers/usb/core/hub.c:4903 > hub_port_connect_change drivers/usb/core/hub.c:5009 > port_event drivers/usb/core/hub.c:5115 > hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 > process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 > worker_thread+0x221/0x1850 kernel/workqueue.c:2253 > kthread+0x3a1/0x470 kernel/kthread.c:231 > ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 > > The buggy address belongs to the object at ffff880063dfa100 > which belongs to the cache kmalloc-8192 of size 8192 > The buggy address is located 2880 bytes inside of > 8192-byte region [ffff880063dfa100, ffff880063dfc100) > The buggy address belongs to the page: > page:ffffea00018f7e00 count:1 mapcount:0 mapping: (null) > index:0x0 compound_mapcount: 0 > flags: 0x100000000008100(slab|head) > raw: 0100000000008100 0000000000000000 0000000000000000 0000000100030003 > raw: ffffea0001afd800 0000000300000003 ffff88006c402a80 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff880063dfab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff880063dfab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >>ffff880063dfac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff880063dfac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff880063dfad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > >> --- >> drivers/net/usb/lan78xx.c | 14 +++++++++----- >> 1 file changed, 9 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c >> index b99a7fb..e653982 100644 >> --- a/drivers/net/usb/lan78xx.c >> +++ b/drivers/net/usb/lan78xx.c >> @@ -402,6 +402,7 @@ struct lan78xx_net { >> struct statstage stats; >> >> struct irq_domain_data domain_data; >> + u8 *buf; >> }; >> >> /* define external phy id */ >> @@ -3470,6 +3471,9 @@ static void lan78xx_disconnect(struct usb_interface *intf) >> >> usb_scuttle_anchored_urbs(&dev->deferred); >> >> + kfree(dev->buf); >> + dev->buf = NULL; >> + >> lan78xx_unbind(dev, intf); >> >> usb_kill_urb(dev->urb_intr); >> @@ -3520,7 +3524,6 @@ static int lan78xx_probe(struct usb_interface *intf, >> int ret; >> unsigned maxp; >> unsigned period; >> - u8 *buf = NULL; >> >> udev = interface_to_usbdev(intf); >> udev = usb_get_dev(udev); >> @@ -3588,16 +3591,15 @@ static int lan78xx_probe(struct usb_interface *intf, >> period = dev->ep_intr->desc.bInterval; >> >> maxp = usb_maxpacket(dev->udev, dev->pipe_intr, 0); >> - buf = kmalloc(maxp, GFP_KERNEL); >> - if (buf) { >> + dev->buf = kmalloc(maxp, GFP_KERNEL); >> + if (dev->buf) { >> dev->urb_intr = usb_alloc_urb(0, GFP_KERNEL); >> if (!dev->urb_intr) { >> ret = -ENOMEM; >> - kfree(buf); >> goto out3; >> } else { >> usb_fill_int_urb(dev->urb_intr, dev->udev, >> - dev->pipe_intr, buf, maxp, >> + dev->pipe_intr, dev->buf, maxp, >> intr_complete, dev, period); >> } >> } >> @@ -3626,6 +3628,8 @@ static int lan78xx_probe(struct usb_interface *intf, >> return 0; >> >> out3: >> + kfree(dev->buf); >> + dev->buf = NULL; >> lan78xx_unbind(dev, intf); >> out2: >> free_netdev(netdev); >> -- >> 1.9.1 >>
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index b99a7fb..e653982 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -402,6 +402,7 @@ struct lan78xx_net { struct statstage stats; struct irq_domain_data domain_data; + u8 *buf; }; /* define external phy id */ @@ -3470,6 +3471,9 @@ static void lan78xx_disconnect(struct usb_interface *intf) usb_scuttle_anchored_urbs(&dev->deferred); + kfree(dev->buf); + dev->buf = NULL; + lan78xx_unbind(dev, intf); usb_kill_urb(dev->urb_intr); @@ -3520,7 +3524,6 @@ static int lan78xx_probe(struct usb_interface *intf, int ret; unsigned maxp; unsigned period; - u8 *buf = NULL; udev = interface_to_usbdev(intf); udev = usb_get_dev(udev); @@ -3588,16 +3591,15 @@ static int lan78xx_probe(struct usb_interface *intf, period = dev->ep_intr->desc.bInterval; maxp = usb_maxpacket(dev->udev, dev->pipe_intr, 0); - buf = kmalloc(maxp, GFP_KERNEL); - if (buf) { + dev->buf = kmalloc(maxp, GFP_KERNEL); + if (dev->buf) { dev->urb_intr = usb_alloc_urb(0, GFP_KERNEL); if (!dev->urb_intr) { ret = -ENOMEM; - kfree(buf); goto out3; } else { usb_fill_int_urb(dev->urb_intr, dev->udev, - dev->pipe_intr, buf, maxp, + dev->pipe_intr, dev->buf, maxp, intr_complete, dev, period); } } @@ -3626,6 +3628,8 @@ static int lan78xx_probe(struct usb_interface *intf, return 0; out3: + kfree(dev->buf); + dev->buf = NULL; lan78xx_unbind(dev, intf); out2: free_netdev(netdev);
We are not releasing 'buf' memory on failure or disconnect a device. Adding 'u8 *buf' as part of 'lan78xx_net' structure to make proper handle for 'buf'. Now releasing 'buf' memory on failure. It's allocate first in lan78xx_probe() and it should be freed last in lan78xx_disconnect(). Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> --- drivers/net/usb/lan78xx.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)