Hello, syzbot found the following issue on: HEAD commit: 996e435f Merge tag 'zonefs-5.11-rc3' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=149f3770d00000 kernel config: https://syzkaller.appspot.com/x/.config?x=bacfc914704718d3 dashboard link: https://syzkaller.appspot.com/bug?extid=60c13361d933487eed83 compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+60c13361d933487eed83@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in skb_dst_drop include/net/dst.h:269 [inline] BUG: KASAN: use-after-free in skb_release_head_state+0x223/0x250 net/core/skbuff.c:653 Read of size 8 at addr ffff888020b57a58 by task syz-executor.3/23125 CPU: 0 PID: 23125 Comm: syz-executor.3 Not tainted 5.11.0-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:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230 __kasan_report mm/kasan/report.c:396 [inline] kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413 skb_dst_drop include/net/dst.h:269 [inline] skb_release_head_state+0x223/0x250 net/core/skbuff.c:653 skb_release_all net/core/skbuff.c:667 [inline] __kfree_skb net/core/skbuff.c:683 [inline] kfree_skb net/core/skbuff.c:701 [inline] kfree_skb+0xfa/0x3f0 net/core/skbuff.c:695 hci_dev_do_open+0xa4a/0x1a00 net/bluetooth/hci_core.c:1619 hci_dev_open+0x132/0x300 net/bluetooth/hci_core.c:1685 hci_sock_ioctl+0x5b6/0x840 net/bluetooth/hci_sock.c:1025 sock_do_ioctl+0xcb/0x2d0 net/socket.c:1037 sock_ioctl+0x477/0x6a0 net/socket.c:1177 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e087 Code: 48 83 c4 08 48 89 d8 5b 5d c3 66 0f 1f 84 00 00 00 00 00 48 89 e8 48 f7 d8 48 39 c3 0f 92 c0 eb 92 66 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 6d b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff4e2da0d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e087 RDX: 0000000000000000 RSI: 00000000400448c9 RDI: 0000000000000003 RBP: 00007fff4e2da0f0 R08: 0000000000000000 R09: 00007fd7d2806700 R10: 00007fd7d28069d0 R11: 0000000000000246 R12: 0000000002df8914 R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 8520: 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:401 [inline] ____kasan_kmalloc.constprop.0+0x82/0xa0 mm/kasan/common.c:429 kasan_slab_alloc include/linux/kasan.h:205 [inline] slab_post_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2891 [inline] slab_alloc mm/slub.c:2899 [inline] kmem_cache_alloc+0x1c6/0x440 mm/slub.c:2904 skb_clone+0x14f/0x3c0 net/core/skbuff.c:1449 hci_cmd_work+0x18f/0x390 net/bluetooth/hci_core.c:5007 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Freed by task 8519: 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:356 ____kasan_slab_free+0xe1/0x110 mm/kasan/common.c:362 kasan_slab_free include/linux/kasan.h:188 [inline] slab_free_hook mm/slub.c:1547 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1580 slab_free mm/slub.c:3142 [inline] kmem_cache_free+0x82/0x350 mm/slub.c:3158 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:684 [inline] kfree_skb net/core/skbuff.c:701 [inline] kfree_skb+0x140/0x3f0 net/core/skbuff.c:695 hci_cmd_work+0x182/0x390 net/bluetooth/hci_core.c:5005 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 The buggy address belongs to the object at ffff888020b57a00 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 88 bytes inside of 232-byte region [ffff888020b57a00, ffff888020b57ae8) The buggy address belongs to the page: page:00000000508c5c1a refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888020b57140 pfn:0x20b57 flags: 0xfff00000000200(slab) raw: 00fff00000000200 ffffea00008b8b88 ffffea000098cd48 ffff888010e75640 raw: ffff888020b57140 00000000000c000b 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888020b57900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888020b57980: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc >ffff888020b57a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888020b57a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff888020b57b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
