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BUG: KASAN: use-after-free in constant_test_bit arch/x86/include/asm/bitops.h:311 [inline]
BUG: KASAN: use-after-free in fuse_dev_do_read.isra.11.constprop.15+0x14b7/0x18b0 fs/fuse/dev.c:1314
Read of size 8 at addr ffff8801c6da9dd8 by task syz-executor0/4798

CPU: 0 PID: 4798 Comm: syz-executor0 Not tainted 4.9.130+ #46
 ffff8801d7d57958 ffffffff81b36c89 ffffea00071b6a00 ffff8801c6da9dd8
 0000000000000000 ffff8801c6da9dd8 ffff8801c82091c8 ffff8801d7d57990
 ffffffff8150080d ffff8801c6da9dd8 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81b36c89>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b36c89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8150080d>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81500c17>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81500c17>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff814f2e24>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff81865557>] constant_test_bit arch/x86/include/asm/bitops.h:311 [inline]
 [<ffffffff81865557>] fuse_dev_do_read.isra.11.constprop.15+0x14b7/0x18b0 fs/fuse/dev.c:1314
 [<ffffffff81865aa6>] fuse_dev_read+0x156/0x1f0 fs/fuse/dev.c:1356
 [<ffffffff81507c34>] new_sync_read fs/read_write.c:439 [inline]
 [<ffffffff81507c34>] __vfs_read+0x3d4/0x560 fs/read_write.c:451
 [<ffffffff8150a5f4>] vfs_read+0x124/0x390 fs/read_write.c:472
 [<ffffffff8150e659>] SYSC_read fs/read_write.c:588 [inline]
 [<ffffffff8150e659>] SyS_read+0xd9/0x1c0 fs/read_write.c:581
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82803013>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Allocated by task 4798:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack mm/kasan/kasan.c:505 [inline]
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:609
 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:594
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547
 slab_post_alloc_hook mm/slab.h:417 [inline]
 slab_alloc_node mm/slub.c:2715 [inline]
 slab_alloc mm/slub.c:2723 [inline]
 kmem_cache_alloc+0xd5/0x2b0 mm/slub.c:2728
 __fuse_request_alloc+0x27/0xe0 fs/fuse/dev.c:58
 fuse_request_alloc+0x18/0x20 fs/fuse/dev.c:86
 fuse_fill_super+0xcd3/0x1640 fs/fuse/inode.c:1144
 mount_nodev+0x5b/0x100 fs/super.c:1146
 fuse_mount+0x2c/0x40 fs/fuse/inode.c:1201
 mount_fs+0x28c/0x370 fs/super.c:1206
 vfs_kern_mount.part.8+0xd1/0x4b0 fs/namespace.c:1000
 vfs_kern_mount fs/namespace.c:982 [inline]
 do_new_mount fs/namespace.c:2537 [inline]
 do_mount+0x3c9/0x28a0 fs/namespace.c:2859
 SYSC_mount fs/namespace.c:3075 [inline]
 SyS_mount+0xea/0x100 fs/namespace.c:3052
 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Freed by task 4805:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack mm/kasan/kasan.c:505 [inline]
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:582
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kmem_cache_free+0xbe/0x310 mm/slub.c:2980
 fuse_request_free+0x8b/0xa0 fs/fuse/dev.c:101
 fuse_put_request+0x261/0x310 fs/fuse/dev.c:298
 request_end+0x34/0x6f0 fs/fuse/dev.c:409
 fuse_dev_do_write+0x12a8/0x2390 fs/fuse/dev.c:1916
 fuse_dev_write+0x142/0x1d0 fs/fuse/dev.c:1940
 new_sync_write fs/read_write.c:496 [inline]
 __vfs_write+0x3d7/0x580 fs/read_write.c:509
 vfs_write+0x187/0x520 fs/read_write.c:557
 SYSC_write fs/read_write.c:604 [inline]
 SyS_write+0xd9/0x1c0 fs/read_write.c:596
 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the object at ffff8801c6da9da8
 which belongs to the cache fuse_request of size 456
The buggy address is located 48 bytes inside of
 456-byte region [ffff8801c6da9da8, ffff8801c6da9f70)
The buggy address belongs to the page:
page:ffffea00071b6a00 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x4000000000004080(slab|head)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c6da9c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c6da9d00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
>ffff8801c6da9d80: fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff8801c6da9e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801c6da9e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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