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BUG: KASAN: use-after-free in dev_uevent+0x30a/0x580 drivers/base/core.c:1671
Read of size 8 at addr ffff88804ac2e098 by task systemd-udevd/6841

CPU: 1 PID: 6841 Comm: systemd-udevd Not tainted 5.8.0-rc7-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+0x1f0/0x31e lib/dump_stack.c:118
 print_address_description+0x66/0x5a0 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 dev_uevent+0x30a/0x580 drivers/base/core.c:1671
 uevent_show+0x1b2/0x2f0 drivers/base/core.c:1742
 dev_attr_show+0x50/0xc0 drivers/base/core.c:1446
 sysfs_kf_seq_show+0x30e/0x4e0 fs/sysfs/file.c:60
 seq_read+0x41a/0xce0 fs/seq_file.c:208
 vfs_read+0x243/0xab0 fs/read_write.c:479
 ksys_read+0x11b/0x220 fs/read_write.c:607
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f4e7c738910
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:00007ffd03861378 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000563d511722d0 RCX: 00007f4e7c738910
RDX: 0000000000001000 RSI: 0000563d5117a1c0 RDI: 0000000000000007
RBP: 00007f4e7c9f3440 R08: 00007f4e7c9f71b8 R09: 0000000000001010
R10: 0000563d511722d0 R11: 0000000000000246 R12: 0000000000001000
R13: 0000000000000d68 R14: 0000563d5117a1c0 R15: 00007f4e7c9f2900

Allocated by task 6740:
 save_stack mm/kasan/common.c:48 [inline]
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494
 kmem_cache_alloc_trace+0x234/0x300 mm/slab.c:3551
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 dev_new drivers/usb/gadget/legacy/raw_gadget.c:182 [inline]
 raw_open+0x87/0x500 drivers/usb/gadget/legacy/raw_gadget.c:372
 misc_open+0x346/0x3c0 drivers/char/misc.c:141
 chrdev_open+0x498/0x580 fs/char_dev.c:414
 do_dentry_open+0x813/0x1070 fs/open.c:828
 do_open fs/namei.c:3243 [inline]
 path_openat+0x278d/0x37f0 fs/namei.c:3360
 do_filp_open+0x191/0x3a0 fs/namei.c:3387
 do_sys_openat2+0x463/0x770 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0x1af/0x1e0 fs/open.c:1199
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 6774:
 save_stack mm/kasan/common.c:48 [inline]
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x220 mm/slab.c:3757
 raw_release+0x130/0x1e0 drivers/usb/gadget/legacy/raw_gadget.c:411
 __fput+0x2f0/0x750 fs/file_table.c:281
 task_work_run+0x137/0x1c0 kernel/task_work.c:135
 exit_task_work include/linux/task_work.h:25 [inline]
 do_exit+0x601/0x1f80 kernel/exit.c:805
 do_group_exit+0x161/0x2d0 kernel/exit.c:903
 get_signal+0x139b/0x1d30 kernel/signal.c:2743
 do_signal+0x33/0x610 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop arch/x86/entry/common.c:235 [inline]
 __prepare_exit_to_usermode+0xd7/0x1e0 arch/x86/entry/common.c:269
 do_syscall_64+0x7f/0xe0 arch/x86/entry/common.c:393
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88804ac2e000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 152 bytes inside of
 4096-byte region [ffff88804ac2e000, ffff88804ac2f000)
The buggy address belongs to the page:
page:ffffea00012b0b80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea00012b0b80 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea000125b908 ffffea00026f1008 ffff8880aa402000
raw: 0000000000000000 ffff88804ac2e000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804ac2df80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804ac2e000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804ac2e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88804ac2e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804ac2e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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