================================================================== BUG: KASAN: double-free or invalid-free in security_tun_dev_free_security+0x3e/0x70 security/security.c:2342 CPU: 1 PID: 18214 Comm: syz-executor.1 Not tainted 5.16.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x2ed mm/kasan/report.c:247 kasan_report_invalid_free+0x51/0x80 mm/kasan/report.c:372 ____kasan_slab_free mm/kasan/common.c:346 [inline] __kasan_slab_free+0xf6/0x110 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] __cache_free mm/slab.c:3445 [inline] kfree+0x10d/0x2c0 mm/slab.c:3802 security_tun_dev_free_security+0x3e/0x70 security/security.c:2342 tun_free_netdev+0xdc/0x140 drivers/net/tun.c:2215 netdev_run_todo+0x6b4/0xa80 net/core/dev.c:10627 __tun_chr_ioctl.isra.0+0x9a1/0x4230 drivers/net/tun.c:3302 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe3f1795ae9 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:00007fe3eed0b188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe3f18a8f60 RCX: 00007fe3f1795ae9 RDX: 00000000200000c0 RSI: 00000000400454ca RDI: 0000000000000005 RBP: 00007fe3f17eff6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc15ad414f R14: 00007fe3eed0b300 R15: 0000000000022000 Allocated by task 18214: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:269 [inline] kmem_cache_alloc_trace+0x1ea/0x4a0 mm/slab.c:3575 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:724 [inline] selinux_tun_dev_alloc_security+0x43/0x180 security/selinux/hooks.c:5594 security_tun_dev_alloc_security+0x40/0x90 security/security.c:2336 __tun_chr_ioctl.isra.0+0x27e6/0x4230 drivers/net/tun.c:2727 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 18214: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xd1/0x110 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] __cache_free mm/slab.c:3445 [inline] kfree+0x10d/0x2c0 mm/slab.c:3802 security_tun_dev_free_security+0x3e/0x70 security/security.c:2342 __tun_chr_ioctl.isra.0+0x2cbf/0x4230 drivers/net/tun.c:2782 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88803ce9ff80 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff88803ce9ff80, ffff88803ce9ffa0) The buggy address belongs to the page: page:ffffea0000f3a7c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88803ce9ffc1 pfn:0x3ce9f flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0000797c48 ffffea00009240c8 ffff888010c40100 raw: ffff88803ce9ffc1 ffff88803ce9f000 0000000100000027 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x242220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 9583, ts 306330414190, free_ts 306305679116 prep_new_page mm/page_alloc.c:2418 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369 __alloc_pages_node include/linux/gfp.h:570 [inline] kmem_getpages mm/slab.c:1377 [inline] cache_grow_begin+0x75/0x470 mm/slab.c:2593 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965 ____cache_alloc mm/slab.c:3048 [inline] ____cache_alloc mm/slab.c:3031 [inline] __do_cache_alloc mm/slab.c:3275 [inline] slab_alloc mm/slab.c:3316 [inline] kmem_cache_alloc_trace+0x380/0x4a0 mm/slab.c:3573 kmalloc include/linux/slab.h:590 [inline] dccp_ackvec_parsed_add+0x54/0x250 net/dccp/ackvec.c:354 ccid2_hc_tx_parse_options+0x8a/0xa0 net/dccp/ccids/ccid2.c:505 ccid_hc_tx_parse_options net/dccp/ccid.h:204 [inline] dccp_parse_options+0x54c/0x13c0 net/dccp/options.c:230 dccp_rcv_established+0x43/0x160 net/dccp/input.c:370 dccp_v6_do_rcv+0x989/0xba0 net/dccp/ipv6.c:621 sk_backlog_rcv include/net/sock.h:1030 [inline] __release_sock+0x134/0x3b0 net/core/sock.c:2768 release_sock+0x54/0x1b0 net/core/sock.c:3300 dccp_sendmsg+0x67a/0xc90 net/dccp/proto.c:796 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x331/0x810 net/socket.c:2409 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3309 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3388 tlb_batch_list_free mm/mmu_gather.c:61 [inline] tlb_finish_mmu+0x24f/0x8c0 mm/mmu_gather.c:343 exit_mmap+0x1ea/0x630 mm/mmap.c:3172 __mmput+0x122/0x4b0 kernel/fork.c:1113 mmput+0x56/0x60 kernel/fork.c:1134 exit_mm kernel/exit.c:507 [inline] do_exit+0xb27/0x2b40 kernel/exit.c:819 do_group_exit+0x125/0x310 kernel/exit.c:929 get_signal+0x47d/0x2220 kernel/signal.c:2852 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff88803ce9fe80: fb fb fb fb fc fc fc fc 00 00 00 02 fc fc fc fc ffff88803ce9ff00: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88803ce9ff80: fa fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88803cea0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88803cea0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================