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BUG: KASAN: use-after-free in usb_udc_uevent+0x11f/0x130 drivers/usb/gadget/udc/core.c:1645
Read of size 8 at addr ffff888014476050 by task systemd-udevd/24105

CPU: 1 PID: 24105 Comm: systemd-udevd Not tainted 5.10.0-rc2-next-20201106-syzkaller #0
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+0x107/0x163 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 usb_udc_uevent+0x11f/0x130 drivers/usb/gadget/udc/core.c:1645
 dev_uevent+0x295/0x780 drivers/base/core.c:1913
 uevent_show+0x1bb/0x390 drivers/base/core.c:1969
 dev_attr_show+0x4b/0x90 drivers/base/core.c:1671
 sysfs_kf_seq_show+0x1f8/0x400 fs/sysfs/file.c:61
 seq_read+0x432/0x1070 fs/seq_file.c:208
 kernfs_fop_read+0xe9/0x590 fs/kernfs/file.c:251
 vfs_read+0x1b5/0x570 fs/read_write.c:494
 ksys_read+0x12d/0x250 fs/read_write.c:634
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f9f58a71910
Code: b6 fe ff ff 48 8d 3d 0f be 08 00 48 83 ec 08 e8 06 db 01 00 66 0f 1f 44 00 00 83 3d f9 2d 2c 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 de 9b 01 00 48 89 04 24
RSP: 002b:00007fff8db3c908 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055cff56c4240 RCX: 00007f9f58a71910
RDX: 0000000000001000 RSI: 000055cff56bd980 RDI: 0000000000000007
RBP: 00007f9f58d2c440 R08: 00007f9f58d30218 R09: 0000000000001010
R10: 000055cff56c4240 R11: 0000000000000246 R12: 0000000000001000
R13: 0000000000000d68 R14: 000055cff56bd980 R15: 00007f9f58d2b900

Allocated by task 24042:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:49
 kasan_set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:480
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 dev_new drivers/usb/gadget/legacy/raw_gadget.c:182 [inline]
 raw_open+0x8d/0x4d0 drivers/usb/gadget/legacy/raw_gadget.c:372
 misc_open+0x372/0x4a0 drivers/char/misc.c:141
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4b9/0x11b0 fs/open.c:817
 do_open fs/namei.c:3252 [inline]
 path_openat+0x1b9a/0x2730 fs/namei.c:3369
 do_filp_open+0x17e/0x3c0 fs/namei.c:3396
 do_sys_openat2+0x16d/0x420 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_open fs/open.c:1192 [inline]
 __se_sys_open fs/open.c:1188 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1188
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 24041:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:49
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:57
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:356
 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:438
 slab_free_hook mm/slub.c:1545 [inline]
 slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1583
 slab_free mm/slub.c:3155 [inline]
 kfree+0xdb/0x360 mm/slub.c:4154
 kref_put include/linux/kref.h:65 [inline]
 raw_release+0x218/0x290 drivers/usb/gadget/legacy/raw_gadget.c:411
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x1f0/0x200 kernel/entry/common.c:199
 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:274
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff888014476000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 80 bytes inside of
 4096-byte region [ffff888014476000, ffff888014477000)
The buggy address belongs to the page:
page:00000000f4b0ebcd refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14470
head:00000000f4b0ebcd order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010042140
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888014475f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888014475f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888014476000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888014476080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888014476100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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