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BUG: KASAN: double-free or invalid-free in security_tun_dev_free_security+0x3e/0x70 security/security.c:2303

CPU: 1 PID: 10504 Comm: syz-executor.4 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:233
 kasan_report_invalid_free+0x51/0x80 mm/kasan/report.c:358
 ____kasan_slab_free mm/kasan/common.c:340 [inline]
 __kasan_slab_free+0xea/0x100 mm/kasan/common.c:367
 kasan_slab_free include/linux/kasan.h:199 [inline]
 __cache_free mm/slab.c:3440 [inline]
 kfree+0x104/0x2b0 mm/slab.c:3798
 security_tun_dev_free_security+0x3e/0x70 security/security.c:2303
 tun_free_netdev+0xdc/0x140 drivers/net/tun.c:2207
 netdev_run_todo+0x8c3/0xdd0 net/core/dev.c:10495
 __tun_chr_ioctl.isra.0+0x9bf/0x4270 drivers/net/tun.c:3295
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4b4a879188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004665f9
RDX: 00000000200000c0 RSI: 00000000400454ca RDI: 0000000000000004
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007fff67ca0cbf R14: 00007f4b4a879300 R15: 0000000000022000

Allocated by task 10504:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:427 [inline]
 ____kasan_kmalloc mm/kasan/common.c:506 [inline]
 ____kasan_kmalloc mm/kasan/common.c:465 [inline]
 __kasan_kmalloc+0x96/0xc0 mm/kasan/common.c:515
 kasan_kmalloc include/linux/kasan.h:233 [inline]
 kmem_cache_alloc_trace+0x209/0x440 mm/slab.c:3570
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:686 [inline]
 selinux_tun_dev_alloc_security+0x43/0x190 security/selinux/hooks.c:5631
 security_tun_dev_alloc_security+0x40/0x90 security/security.c:2297
 __tun_chr_ioctl.isra.0+0x27d9/0x4270 drivers/net/tun.c:2719
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 10504:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
 ____kasan_slab_free mm/kasan/common.c:360 [inline]
 ____kasan_slab_free mm/kasan/common.c:325 [inline]
 __kasan_slab_free+0xc7/0x100 mm/kasan/common.c:367
 kasan_slab_free include/linux/kasan.h:199 [inline]
 __cache_free mm/slab.c:3440 [inline]
 kfree+0x104/0x2b0 mm/slab.c:3798
 security_tun_dev_free_security+0x3e/0x70 security/security.c:2303
 __tun_chr_ioctl.isra.0+0x2d2a/0x4270 drivers/net/tun.c:2774
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888018296a80
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff888018296a80, ffff888018296aa0)
The buggy address belongs to the page:
page:ffffea000060a580 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888018296fc1 pfn:0x18296
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00006ebf08 ffffea0000691108 ffff888011040100
raw: ffff888018296fc1 ffff888018296000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888018296980: fa fb fb fb fc fc fc fc 00 01 fc fc fc fc fc fc
 ffff888018296a00: 00 00 01 fc fc fc fc fc fa fb fb fb fc fc fc fc
>ffff888018296a80: fa fb fb fb fc fc fc fc 06 fc fc fc fc fc fc fc
                   ^
 ffff888018296b00: 00 01 fc fc fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff888018296b80: 00 00 01 fc fc fc fc fc fa fb fb fb fc fc fc fc
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