3.16.79-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Hillf Danton hdanton@sina.com
commit 9c09b214f30e3c11f9b0b03f89442df03643794d upstream.
syzbot found the following crash on:
HEAD commit: e96407b4 usb-fuzzer: main usb gadget fuzzer driver git tree: https://github.com/google/kasan.git usb-fuzzer console output: https://syzkaller.appspot.com/x/log.txt?x=147ac20c600000 kernel config: https://syzkaller.appspot.com/x/.config?x=792eb47789f57810 dashboard link: https://syzkaller.appspot.com/bug?extid=62a1e04fd3ec2abf099e compiler: gcc (GCC) 9.0.0 20181231 (experimental)
================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x302a/0x3b50 kernel/locking/lockdep.c:3753 Read of size 8 at addr ffff8881cf591a08 by task syz-executor.1/26260
CPU: 1 PID: 26260 Comm: syz-executor.1 Not tainted 5.3.0-rc2+ #24 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e lib/dump_stack.c:113 print_address_description+0x6a/0x32c mm/kasan/report.c:351 __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482 kasan_report+0xe/0x12 mm/kasan/common.c:612 __lock_acquire+0x302a/0x3b50 kernel/locking/lockdep.c:3753 lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x32/0x50 kernel/locking/spinlock.c:159 hiddev_release+0x82/0x520 drivers/hid/usbhid/hiddev.c:221 __fput+0x2d7/0x840 fs/file_table.c:280 task_work_run+0x13f/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x8ef/0x2c50 kernel/exit.c:878 do_group_exit+0x125/0x340 kernel/exit.c:982 get_signal+0x466/0x23d0 kernel/signal.c:2728 do_signal+0x88/0x14e0 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x1a2/0x200 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x45f/0x580 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f75b2a6ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000075c078 RCX: 0000000000459829 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075c078 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075c07c R13: 00007ffcdfe1023f R14: 00007f75b2a6d9c0 R15: 000000000075c07c
Allocated by task 104: save_stack+0x1b/0x80 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:487 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:748 [inline] hiddev_connect+0x242/0x5b0 drivers/hid/usbhid/hiddev.c:900 hid_connect+0x239/0xbb0 drivers/hid/hid-core.c:1882 hid_hw_start drivers/hid/hid-core.c:1981 [inline] hid_hw_start+0xa2/0x130 drivers/hid/hid-core.c:1972 appleir_probe+0x13e/0x1a0 drivers/hid/hid-appleir.c:308 hid_device_probe+0x2be/0x3f0 drivers/hid/hid-core.c:2209 really_probe+0x281/0x650 drivers/base/dd.c:548 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:882 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2114 hid_add_device+0x33c/0x990 drivers/hid/hid-core.c:2365 usbhid_probe+0xa81/0xfa0 drivers/hid/usbhid/hid-core.c:1386 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 really_probe+0x281/0x650 drivers/base/dd.c:548 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:882 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2114 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 really_probe+0x281/0x650 drivers/base/dd.c:548 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:882 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2114 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 hub_port_connect drivers/usb/core/hub.c:5098 [inline] hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] port_event drivers/usb/core/hub.c:5359 [inline] hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 worker_thread+0x96/0xe20 kernel/workqueue.c:2415 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Freed by task 104: save_stack+0x1b/0x80 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_slab_free+0x130/0x180 mm/kasan/common.c:449 slab_free_hook mm/slub.c:1423 [inline] slab_free_freelist_hook mm/slub.c:1470 [inline] slab_free mm/slub.c:3012 [inline] kfree+0xe4/0x2f0 mm/slub.c:3953 hiddev_connect.cold+0x45/0x5c drivers/hid/usbhid/hiddev.c:914 hid_connect+0x239/0xbb0 drivers/hid/hid-core.c:1882 hid_hw_start drivers/hid/hid-core.c:1981 [inline] hid_hw_start+0xa2/0x130 drivers/hid/hid-core.c:1972 appleir_probe+0x13e/0x1a0 drivers/hid/hid-appleir.c:308 hid_device_probe+0x2be/0x3f0 drivers/hid/hid-core.c:2209 really_probe+0x281/0x650 drivers/base/dd.c:548 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:882 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2114 hid_add_device+0x33c/0x990 drivers/hid/hid-core.c:2365 usbhid_probe+0xa81/0xfa0 drivers/hid/usbhid/hid-core.c:1386 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 really_probe+0x281/0x650 drivers/base/dd.c:548 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:882 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2114 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 really_probe+0x281/0x650 drivers/base/dd.c:548 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:882 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2114 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 hub_port_connect drivers/usb/core/hub.c:5098 [inline] hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] port_event drivers/usb/core/hub.c:5359 [inline] hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 worker_thread+0x96/0xe20 kernel/workqueue.c:2415 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
The buggy address belongs to the object at ffff8881cf591900 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff8881cf591900, ffff8881cf591b00) The buggy address belongs to the page: page:ffffea00073d6400 refcount:1 mapcount:0 mapping:ffff8881da002500 index:0x0 compound_mapcount: 0 flags: 0x200000000010200(slab|head) raw: 0200000000010200 0000000000000000 0000000100000001 ffff8881da002500 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff8881cf591900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cf591980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881cf591a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^ ffff8881cf591a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cf591b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================
In order to avoid opening a disconnected device, we need to check exist again after acquiring the existance lock, and bail out if necessary.
Reported-by: syzbot syzbot+62a1e04fd3ec2abf099e@syzkaller.appspotmail.com Cc: Andrey Konovalov andreyknvl@google.com Signed-off-by: Hillf Danton hdanton@sina.com Signed-off-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/hid/usbhid/hiddev.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -308,6 +308,14 @@ static int hiddev_open(struct inode *ino spin_unlock_irq(&list->hiddev->list_lock);
mutex_lock(&hiddev->existancelock); + /* + * recheck exist with existance lock held to + * avoid opening a disconnected device + */ + if (!list->hiddev->exist) { + res = -ENODEV; + goto bail_unlock; + } if (!list->hiddev->open++) if (list->hiddev->exist) { struct hid_device *hid = hiddev->hid;