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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 ffff888021438990 by task syz-executor.3/24685

CPU: 1 PID: 24685 Comm: syz-executor.3 Not tainted 5.9.0-rc7-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
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
 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+0x1079/0x1ecf 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:2875 [inline]
 path_mount+0x1387/0x20a0 fs/namespace.c:3192
 do_mount+0xf3/0x110 fs/namespace.c:3205
 __do_compat_sys_mount fs/compat.c:122 [inline]
 __se_compat_sys_mount fs/compat.c:89 [inline]
 __ia32_compat_sys_mount+0x193/0x710 fs/compat.c:89
 do_syscall_32_irqs_on arch/x86/entry/common.c:78 [inline]
 __do_fast_syscall_32+0x60/0x90 arch/x86/entry/common.c:137
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:160
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7fc5549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f55bef00 EFLAGS: 00000292 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00000000f55bef70 RCX: 0000000020000100
RDX: 0000000020000000 RSI: 0000000000000000 RDI: 00000000f55befb0
RBP: 00000000f55befb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4255:
 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:3659 [inline]
 __kmalloc_track_caller+0x1ae/0x360 mm/slab.c:3674
 kmemdup+0x23/0x50 mm/util.c:127
 kmemdup include/linux/string.h:479 [inline]
 shmem_symlink+0x185/0x7c0 mm/shmem.c:3158
 vfs_symlink fs/namei.c:3959 [inline]
 vfs_symlink+0x44e/0x690 fs/namei.c:3945
 do_symlinkat+0x258/0x2c0 fs/namei.c:3986
 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 ffff888021438980
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 16 bytes inside of
 32-byte region [ffff888021438980, ffff8880214389a0)
The buggy address belongs to the page:
page:0000000050ef872f refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888021438fc1 pfn:0x21438
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00009f6208 ffffea0000941d88 ffff88802c840100
raw: ffff888021438fc1 ffff888021438000 000000010000003c ffff888027e1c401
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff888027e1c401

Memory state around the buggy address:
 ffff888021438880: 00 01 fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
 ffff888021438900: 00 00 00 fc fc fc fc fc 00 fc fc fc fc fc fc fc
>ffff888021438980: 00 01 fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
                         ^
 ffff888021438a00: 00 01 fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
 ffff888021438a80: fa fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
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