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BUG: KASAN: slab-out-of-bounds in ntfs_attr_find+0x9e9/0xb20 fs/ntfs/attrib.c:599
Read of size 4 at addr ffff8880900f9fff by task syz-executor.2/9644

CPU: 1 PID: 9644 Comm: syz-executor.2 Not tainted 5.9.0-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+0x198/0x1fd lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 ntfs_attr_find+0x9e9/0xb20 fs/ntfs/attrib.c:599
 ntfs_attr_lookup+0x1051/0x2060 fs/ntfs/attrib.c:1189
 ntfs_read_inode_mount+0x730/0x22b0 fs/ntfs/inode.c:1833
 ntfs_fill_super+0xa63/0x8560 fs/ntfs/super.c:2857
 mount_bdev+0x32e/0x3f0 fs/super.c:1417
 legacy_get_tree+0x105/0x220 fs/fs_context.c:592
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 do_new_mount fs/namespace.c:2875 [inline]
 path_mount+0x1387/0x20a0 fs/namespace.c:3192
 do_mount fs/namespace.c:3205 [inline]
 __do_sys_mount fs/namespace.c:3413 [inline]
 __se_sys_mount fs/namespace.c:3390 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4607ea
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f863e20aa88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f863e20ab20 RCX: 00000000004607ea
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f863e20aae0
RBP: 00007f863e20aae0 R08: 00007f863e20ab20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020086400

Allocated by task 31958:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xae/0x550 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 alloc_uevent_skb+0x7b/0x210 lib/kobject_uevent.c:289
 uevent_net_broadcast_untagged lib/kobject_uevent.c:325 [inline]
 kobject_uevent_net_broadcast lib/kobject_uevent.c:408 [inline]
 kobject_uevent_env+0x99d/0x1400 lib/kobject_uevent.c:592
 __loop_clr_fd+0x5dd/0xe60 drivers/block/loop.c:1256
 loop_clr_fd drivers/block/loop.c:1345 [inline]
 lo_ioctl+0x3b7/0x16b0 drivers/block/loop.c:1703
 __blkdev_driver_ioctl block/ioctl.c:224 [inline]
 blkdev_ioctl+0x28c/0x700 block/ioctl.c:620
 block_ioctl+0xf9/0x140 fs/block_dev.c:1871
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880900f9c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 511 bytes to the right of
 512-byte region [ffff8880900f9c00, ffff8880900f9e00)
The buggy address belongs to the page:
page:000000006648030c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x900f9
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00027a9dc8 ffffea0002a0b408 ffff8880aa040600
raw: 0000000000000000 ffff8880900f9000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880900f9e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880900f9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880900f9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                                ^
 ffff8880900fa000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880900fa080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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