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BUG: KASAN: slab-out-of-bounds in squashfs_get_id+0x1ae/0x1d0 fs/squashfs/id.c:38
Read of size 8 at addr ffff88804993e260 by task syz-executor.3/8744

CPU: 0 PID: 8744 Comm: syz-executor.3 Not tainted 5.9.0-rc6-next-20200924-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+0x198/0x1fb lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 squashfs_get_id+0x1ae/0x1d0 fs/squashfs/id.c:38
 squashfs_new_inode fs/squashfs/inode.c:51 [inline]
 squashfs_read_inode+0x197/0x1940 fs/squashfs/inode.c:120
 squashfs_fill_super+0x1079/0x1ed0 fs/squashfs/super.c:310
 get_tree_bdev+0x421/0x740 fs/super.c:1342
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 do_new_mount fs/namespace.c:2896 [inline]
 path_mount+0x12ae/0x1e70 fs/namespace.c:3227
 __do_sys_mount fs/namespace.c:3438 [inline]
 __se_sys_mount fs/namespace.c:3411 [inline]
 __x64_sys_mount+0x278/0x2f0 fs/namespace.c:3411
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x460bca
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 dd 87 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 ba 87 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f15c2637a88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f15c2637b20 RCX: 0000000000460bca
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f15c2637ae0
RBP: 00007f15c2637ae0 R08: 00007f15c2637b20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020000240

Allocated by task 8744:
 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
 __do_kmalloc mm/slab.c:3653 [inline]
 __kmalloc+0x27c/0x4d0 mm/slab.c:3662
 kmalloc include/linux/slab.h:559 [inline]
 squashfs_read_table+0x43/0x1e0 fs/squashfs/cache.c:413
 squashfs_read_id_index_table+0x83/0xf0 fs/squashfs/id.c:77
 squashfs_fill_super+0xce9/0x1ed0 fs/squashfs/super.c:238
 get_tree_bdev+0x421/0x740 fs/super.c:1342
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 do_new_mount fs/namespace.c:2896 [inline]
 path_mount+0x12ae/0x1e70 fs/namespace.c:3227
 __do_sys_mount fs/namespace.c:3438 [inline]
 __se_sys_mount fs/namespace.c:3411 [inline]
 __x64_sys_mount+0x278/0x2f0 fs/namespace.c:3411
 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 ffff88804993e240
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes to the right of
 32-byte region [ffff88804993e240, ffff88804993e260)
The buggy address belongs to the page:
page:000000007377fca1 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804993efc1 pfn:0x4993e
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea000042c608 ffffea0000419008 ffff8880aa040100
raw: ffff88804993efc1 ffff88804993e000 000000010000003a 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804993e100: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff88804993e180: 00 00 fc fc fc fc fc fc fa fb fb fb fc fc fc fc
>ffff88804993e200: fa fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
                                                       ^
 ffff88804993e280: 00 00 fc fc fc fc fc fc fa fb fb fb fc fc fc fc
 ffff88804993e300: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
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