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BUG: KASAN: use-after-free in fuse_request_end+0x825/0x990 fs/fuse/dev.c:279
Read of size 8 at addr ffff8880a2279f68 by task syz-executor.0/8675

CPU: 0 PID: 8675 Comm: syz-executor.0 Not tainted 5.4.0-rc3+ #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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:634
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 fuse_request_end+0x825/0x990 fs/fuse/dev.c:279
 fuse_dev_do_read.isra.0+0x115b/0x1df0 fs/fuse/dev.c:1295
 fuse_dev_read+0x165/0x200 fs/fuse/dev.c:1328
 call_read_iter include/linux/fs.h:1889 [inline]
 new_sync_read+0x4d7/0x800 fs/read_write.c:414
 __vfs_read+0xe1/0x110 fs/read_write.c:427
 vfs_read+0x1f0/0x440 fs/read_write.c:461
 ksys_read+0x14f/0x290 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __ia32_sys_read+0x71/0xb0 fs/read_write.c:595
 do_syscall_32_irqs_on arch/x86/entry/common.c:333 [inline]
 do_fast_syscall_32+0x27b/0xdb3 arch/x86/entry/common.c:404
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f59a29
Code: b8 80 96 98 00 eb cc 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5d340cc EFLAGS: 00000296 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000200030c0
RDX: 00000000fffffed0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 8675:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:510 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524
 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3550
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:690 [inline]
 fuse_send_init+0x48/0x440 fs/fuse/inode.c:974
 fuse_fill_super+0x2a6/0x3a0 fs/fuse/inode.c:1257
 vfs_get_super+0x13e/0x2e0 fs/super.c:1189
 get_tree_nodev+0x23/0x30 fs/super.c:1219
 fuse_get_tree+0x12e/0x190 fs/fuse/inode.c:1282
 vfs_get_tree+0x8e/0x300 fs/super.c:1545
 do_new_mount fs/namespace.c:2823 [inline]
 do_mount+0x143d/0x1d10 fs/namespace.c:3143
 __do_compat_sys_mount fs/compat.c:122 [inline]
 __se_compat_sys_mount fs/compat.c:89 [inline]
 __ia32_compat_sys_mount+0x664/0x790 fs/compat.c:89
 do_syscall_32_irqs_on arch/x86/entry/common.c:333 [inline]
 do_fast_syscall_32+0x27b/0xdb3 arch/x86/entry/common.c:404
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 8672:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3756
 process_init_reply+0xfb/0x1620 fs/fuse/inode.c:964
 fuse_request_end+0x388/0x990 fs/fuse/dev.c:326
 end_requests+0x16c/0x240 fs/fuse/dev.c:2049
 fuse_abort_conn+0xa4d/0xdb0 fs/fuse/dev.c:2144
 fuse_sb_destroy+0xa3/0x120 fs/fuse/inode.c:1325
 fuse_kill_sb_anon+0x16/0x30 fs/fuse/inode.c:1336
 deactivate_locked_super+0x95/0x100 fs/super.c:335
 deactivate_super fs/super.c:366 [inline]
 deactivate_super+0x1b2/0x1d0 fs/super.c:362
 cleanup_mnt+0x351/0x4c0 fs/namespace.c:1102
 __cleanup_mnt+0x16/0x20 fs/namespace.c:1109
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 get_signal+0x2078/0x2500 kernel/signal.c:2528
 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x286/0x380 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_32_irqs_on arch/x86/entry/common.c:348 [inline]
 do_fast_syscall_32+0xb87/0xdb3 arch/x86/entry/common.c:404
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff8880a2279f00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 104 bytes inside of
 192-byte region [ffff8880a2279f00, ffff8880a2279fc0)
The buggy address belongs to the page:
page:ffffea0002889e40 refcount:1 mapcount:0 mapping:ffff8880aa400000 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00028e6e08 ffffea00025033c8 ffff8880aa400000
raw: 0000000000000000 ffff8880a2279000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a2279e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a2279e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a2279f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff8880a2279f80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880a227a000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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