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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 ffff88804e77f8f8 by task syz-executor.3/25799

CPU: 0 PID: 25799 Comm: syz-executor.3 Not tainted 5.9.0-rc5-next-20200921-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:55 [inline]
 squashfs_read_inode+0x1d3/0x1940 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_mount fs/namespace.c:3240 [inline]
 __do_sys_mount fs/namespace.c:3448 [inline]
 __se_sys_mount fs/namespace.c:3425 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3425
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x46004a
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd 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 da 89 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f8692b75a88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8692b75b20 RCX: 000000000046004a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f8692b75ae0
RBP: 00007f8692b75ae0 R08: 00007f8692b75b20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000040 R15: 0000000020000240

Allocated by task 785:
 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
 kmem_cache_alloc_trace+0x1a0/0x480 mm/slab.c:3548
 kmalloc include/linux/slab.h:554 [inline]
 tcf_block_owner_add net/sched/cls_api.c:1276 [inline]
 tcf_block_get_ext+0x14a/0x17c0 net/sched/cls_api.c:1324
 tcf_block_get+0xa5/0xf0 net/sched/cls_api.c:1369
 hfsc_init_qdisc+0x155/0x410 net/sched/sch_hfsc.c:1404
 qdisc_create+0x4ba/0x1270 net/sched/sch_api.c:1246
 tc_modify_qdisc+0x4c8/0x1990 net/sched/sch_api.c:1662
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5563
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2470
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x331/0x810 net/socket.c:2362
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2416
 __sys_sendmmsg+0x196/0x4b0 net/socket.c:2506
 __do_sys_sendmmsg net/socket.c:2535 [inline]
 __se_sys_sendmmsg net/socket.c:2532 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2532
 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 ffff88804e77f8c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes to the right of
 32-byte region [ffff88804e77f8c0, ffff88804e77f8e0)
The buggy address belongs to the page:
page:0000000022176fa3 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804e77ffc1 pfn:0x4e77f
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00028e14c8 ffffea00026ad048 ffff8880aa040100
raw: ffff88804e77ffc1 ffff88804e77f000 0000000100000033 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804e77f780: fb fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
 ffff88804e77f800: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
>ffff88804e77f880: fb fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
                                                                ^
 ffff88804e77f900: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff88804e77f980: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
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