================================================================== BUG: KASAN: double-free or invalid-free in security_tun_dev_free_security+0x3e/0x70 security/security.c:2341 CPU: 0 PID: 10118 Comm: syz-executor.1 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 print_address_description.constprop.0.cold+0x6c/0x2d6 mm/kasan/report.c:256 kasan_report_invalid_free+0x51/0x80 mm/kasan/report.c:381 ____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:230 [inline] __cache_free mm/slab.c:3445 [inline] kfree+0x10a/0x2c0 mm/slab.c:3803 security_tun_dev_free_security+0x3e/0x70 security/security.c:2341 tun_free_netdev+0xdc/0x140 drivers/net/tun.c:2210 netdev_run_todo+0x6b4/0xa80 net/core/dev.c:10589 __tun_chr_ioctl.isra.0+0x993/0x4230 drivers/net/tun.c:3297 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: 0033:0x4665f9 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:00007fb0daa8b188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000020000040 RSI: 00000000400454ca RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffc2bdf08df R14: 00007fb0daa8b300 R15: 0000000000022000 Allocated by task 10118: 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:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa1/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:264 [inline] kmem_cache_alloc_trace+0x1e4/0x480 mm/slab.c:3575 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] selinux_tun_dev_alloc_security+0x43/0x180 security/selinux/hooks.c:5611 security_tun_dev_alloc_security+0x40/0x90 security/security.c:2335 __tun_chr_ioctl.isra.0+0x27d8/0x4230 drivers/net/tun.c:2722 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 10118: 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:360 ____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:230 [inline] __cache_free mm/slab.c:3445 [inline] kfree+0x10a/0x2c0 mm/slab.c:3803 security_tun_dev_free_security+0x3e/0x70 security/security.c:2341 __tun_chr_ioctl.isra.0+0x2cdf/0x4230 drivers/net/tun.c:2777 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 ffff88807eab8a40 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff88807eab8a40, ffff88807eab8a60) The buggy address belongs to the page: page:ffffea0001faae00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807eab8fc1 pfn:0x7eab8 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00006341c8 ffffea00008d8c08 ffff888010c40100 raw: ffff88807eab8fc1 ffff88807eab8000 000000010000003e 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 0x242040(__GFP_IO|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 1, ts 19588928857, free_ts 19236531399 prep_new_page mm/page_alloc.c:2436 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4168 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5390 __alloc_pages_node include/linux/gfp.h:570 [inline] kmem_getpages mm/slab.c:1377 [inline] cache_grow_begin+0x75/0x460 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] __do_kmalloc mm/slab.c:3700 [inline] __kmalloc+0x3d5/0x4d0 mm/slab.c:3711 kmalloc include/linux/slab.h:596 [inline] kzalloc include/linux/slab.h:721 [inline] tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline] tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x186/0x620 security/tomoyo/realpath.c:288 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1333 vfs_getattr fs/stat.c:157 [inline] vfs_statx+0x164/0x390 fs/stat.c:225 vfs_fstatat fs/stat.c:243 [inline] __do_sys_newfstatat+0x96/0x120 fs/stat.c:412 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 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1346 [inline] free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397 free_unref_page_prepare mm/page_alloc.c:3332 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3411 __vunmap+0x783/0xb70 mm/vmalloc.c:2609 __vfree+0x3c/0xd0 mm/vmalloc.c:2657 vfree+0x5a/0x90 mm/vmalloc.c:2688 sel_write_load+0xa2a/0x1e70 security/selinux/selinuxfs.c:667 vfs_write+0x28e/0xae0 fs/read_write.c:592 ksys_write+0x12d/0x250 fs/read_write.c:647 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 Memory state around the buggy address: ffff88807eab8900: fa fb fb fb fc fc fc fc 00 00 01 fc fc fc fc fc ffff88807eab8980: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88807eab8a00: 00 00 01 fc fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88807eab8a80: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88807eab8b00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================