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BUG: KASAN: use-after-free in fuse_request_end+0x7f/0xfe0 fs/fuse/dev.c:279
Read of size 8 at addr ffff88809f8b7f68 by task syz-executor.0/10861

CPU: 1 PID: 10861 Comm: syz-executor.0 Not tainted 5.4.0-rc4 #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+0x1d8/0x2f8 lib/dump_stack.c:113
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 fuse_request_end+0x7f/0xfe0 fs/fuse/dev.c:279
 fuse_dev_do_read+0x29ce/0x43a0 fs/fuse/dev.c:1295
 fuse_dev_read+0x123/0x1a0 fs/fuse/dev.c:1328
 call_read_iter include/linux/fs.h:1889 [inline]
 new_sync_read fs/read_write.c:414 [inline]
 __vfs_read+0x59e/0x730 fs/read_write.c:427
 vfs_read+0x1dd/0x420 fs/read_write.c:461
 ksys_read+0x117/0x220 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x7b/0x90 fs/read_write.c:595
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459cd9
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:00007f9841cefc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459cd9
RDX: 00000000fffffed0 RSI: 00000000200030c0 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9841cf06d4
R13: 00000000004c7366 R14: 00000000004dce30 R15: 00000000ffffffff

Allocated by task 10861:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524
 kmem_cache_alloc_trace+0x221/0x2f0 mm/slab.c:3550
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:690 [inline]
 fuse_send_init+0x54/0x450 fs/fuse/inode.c:974
 fuse_fill_super+0x314/0x450 fs/fuse/inode.c:1257
 vfs_get_super fs/super.c:1189 [inline]
 get_tree_nodev+0xb7/0x170 fs/super.c:1219
 fuse_get_tree+0x92/0xe0 fs/fuse/inode.c:1282
 vfs_get_tree+0x8b/0x2a0 fs/super.c:1545
 do_new_mount fs/namespace.c:2823 [inline]
 do_mount+0x16c0/0x2510 fs/namespace.c:3143
 ksys_mount+0xcc/0x100 fs/namespace.c:3352
 __do_sys_mount fs/namespace.c:3366 [inline]
 __se_sys_mount fs/namespace.c:3363 [inline]
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3363
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 10860:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x115/0x200 mm/slab.c:3756
 process_init_reply+0x1136/0x1ae0 fs/fuse/inode.c:964
 fuse_request_end+0x3ad/0xfe0 fs/fuse/dev.c:326
 end_requests fs/fuse/dev.c:2049 [inline]
 fuse_abort_conn+0x14b5/0x1610 fs/fuse/dev.c:2144
 fuse_sb_destroy fs/fuse/inode.c:1325 [inline]
 fuse_kill_sb_anon+0x130/0x220 fs/fuse/inode.c:1336
 deactivate_locked_super+0xa8/0x100 fs/super.c:335
 deactivate_super+0x16c/0x200 fs/super.c:366
 cleanup_mnt+0x43b/0x4f0 fs/namespace.c:1102
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1109
 task_work_run+0x17e/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
 prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274
 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809f8b7f00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 104 bytes inside of
 192-byte region [ffff88809f8b7f00, ffff88809f8b7fc0)
The buggy address belongs to the page:
page:ffffea00027e2dc0 refcount:1 mapcount:0 mapping:ffff8880aa400000 index:0xffff88809f8b7200
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00027a1348 ffffea0002925188 ffff8880aa400000
raw: ffff88809f8b7200 ffff88809f8b7000 0000000100000007 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809f8b7e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809f8b7e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88809f8b7f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff88809f8b7f80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88809f8b8000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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