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BUG: KASAN: slab-out-of-bounds in squashfs_get_id+0x1ae/0x1d0 fs/squashfs/id.c:51
Read of size 8 at addr ffff8880a0d02820 by task syz-executor.3/13984

CPU: 0 PID: 13984 Comm: syz-executor.3 Not tainted 4.19.166-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+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 squashfs_get_id+0x1ae/0x1d0 fs/squashfs/id.c:51
 squashfs_new_inode fs/squashfs/inode.c:64 [inline]
 squashfs_read_inode+0x1b4/0x1b40 fs/squashfs/inode.c:133
 squashfs_fill_super+0x1655/0x1c00 fs/squashfs/super.c:318
 mount_bdev+0x2fc/0x3b0 fs/super.c:1158
 mount_fs+0xa3/0x30c fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x113c/0x2f10 fs/namespace.c:2799
 ksys_mount+0xcf/0x130 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x460c6a
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:00007f29073d1a78 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f29073d1b10 RCX: 0000000000460c6a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f29073d1ad0
RBP: 00007f29073d1ad0 R08: 00007f29073d1b10 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020010300

Allocated by task 3564:
 kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 aa_alloc_task_ctx security/apparmor/include/task.h:47 [inline]
 apparmor_task_alloc+0x41/0x290 security/apparmor/lsm.c:100
 security_task_alloc+0x48/0xa0 security/security.c:987
 copy_process.part.0+0x1dc0/0x8200 kernel/fork.c:1898
 copy_process kernel/fork.c:1713 [inline]
 _do_fork+0x22f/0xf30 kernel/fork.c:2228
 kernel_thread+0x2f/0x40 kernel/fork.c:2287
 call_usermodehelper_exec_work kernel/umh.c:199 [inline]
 call_usermodehelper_exec_work+0x16d/0x260 kernel/umh.c:185
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Freed by task 9:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 aa_free_task_ctx security/apparmor/include/task.h:61 [inline]
 apparmor_task_free+0x143/0x1e0 security/apparmor/lsm.c:93
 security_task_free+0x3e/0x70 security/security.c:992
 __put_task_struct+0xea/0x340 kernel/fork.c:688
 put_task_struct include/linux/sched/task.h:98 [inline]
 delayed_put_task_struct+0x1dc/0x320 kernel/exit.c:181
 __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
 rcu_do_batch kernel/rcu/tree.c:2584 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
 rcu_process_callbacks+0x8ff/0x18b0 kernel/rcu/tree.c:2881
 __do_softirq+0x26c/0x9a0 kernel/softirq.c:292

The buggy address belongs to the object at ffff8880a0d02800
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes to the right of
 32-byte region [ffff8880a0d02800, ffff8880a0d02820)
The buggy address belongs to the page:
page:ffffea0002834080 count:1 mapcount:0 mapping:ffff88813bff01c0 index:0xffff8880a0d02fc1
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002945cc8 ffffea0002a47748 ffff88813bff01c0
raw: ffff8880a0d02fc1 ffff8880a0d02000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a0d02700: 00 00 00 06 fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8880a0d02780: fb fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
>ffff8880a0d02800: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
                               ^
 ffff8880a0d02880: fb fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
 ffff8880a0d02900: 00 00 00 fc fc fc fc fc 00 00 fc fc fc fc fc fc
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