================================================================== BUG: KASAN: slab-use-after-free in qfq_reset_qdisc+0x323/0x420 net/sched/sch_qfq.c:1484 Read of size 8 at addr ffff8880523f9950 by task syz.1.2605/13492 CPU: 3 UID: 0 PID: 13492 Comm: syz.1.2605 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 qfq_reset_qdisc+0x323/0x420 net/sched/sch_qfq.c:1484 qdisc_reset+0xe0/0x660 net/sched/sch_generic.c:1041 __qdisc_destroy+0xd3/0x4d0 net/sched/sch_generic.c:1080 qdisc_put+0xab/0xe0 net/sched/sch_generic.c:1112 dev_shutdown+0x1d0/0x430 net/sched/sch_generic.c:1500 unregister_netdevice_many_notify+0xb12/0x25c0 net/core/dev.c:12272 unregister_netdevice_many net/core/dev.c:12347 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:12161 unregister_netdevice include/linux/netdevice.h:3389 [inline] __tun_detach+0x119c/0x1490 drivers/net/tun.c:621 tun_detach drivers/net/tun.c:637 [inline] tun_chr_close+0xc2/0x230 drivers/net/tun.c:3436 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd7b5f8f749 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcd05aa228 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fd7b61e7da0 RCX: 00007fd7b5f8f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fd7b61e7da0 R08: 0000000000000000 R09: 0000000ed05aa51f R10: 000000000003fd70 R11: 0000000000000246 R12: 0000000000045d82 R13: 00007ffcd05aa320 R14: ffffffffffffffff R15: 00007ffcd05aa340 Allocated by task 13494: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] qfq_change_class+0x2ba/0x1ec0 net/sched/sch_qfq.c:479 __tc_ctl_tclass net/sched/sch_api.c:2279 [inline] tc_ctl_tclass+0x59d/0x16c0 net/sched/sch_api.c:2309 rtnetlink_rcv_msg+0x3c9/0xe90 net/core/rtnetlink.c:6960 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmsg+0x16d/0x220 net/socket.c:2716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 13494: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2543 [inline] slab_free mm/slub.c:6642 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6849 qfq_change_class+0x1577/0x1ec0 net/sched/sch_qfq.c:533 __tc_ctl_tclass net/sched/sch_api.c:2279 [inline] tc_ctl_tclass+0x59d/0x16c0 net/sched/sch_api.c:2309 rtnetlink_rcv_msg+0x3c9/0xe90 net/core/rtnetlink.c:6960 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmsg+0x16d/0x220 net/socket.c:2716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880523f9900 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 80 bytes inside of freed 128-byte region [ffff8880523f9900, ffff8880523f9980) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x523f9 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b442a00 ffffea0001490540 dead000000000004 raw: 0000000000000000 0000000080100010 00000000f5000000 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6020, tgid 6019 (syz.0.1), ts 49986783818, free_ts 49986757307 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5178 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3059 [inline] allocate_slab mm/slub.c:3232 [inline] new_slab+0x24a/0x360 mm/slub.c:3286 ___slab_alloc+0xd79/0x1a50 mm/slub.c:4655 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] __kmalloc_cache_noprof+0x477/0x780 mm/slub.c:5766 kmalloc_noprof include/linux/slab.h:957 [inline] __hw_addr_create net/core/dev_addr_lists.c:60 [inline] __hw_addr_add_ex+0x3c9/0x7c0 net/core/dev_addr_lists.c:118 __hw_addr_add net/core/dev_addr_lists.c:135 [inline] dev_addr_init+0x161/0x250 net/core/dev_addr_lists.c:559 alloc_netdev_mqs+0x363/0x1550 net/core/dev.c:11917 ip6_tnl_init_net+0xf5/0x4d0 net/ipv6/ip6_tunnel.c:2291 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x100/0x390 net/core/net_namespace.c:445 copy_net_ns+0x2f8/0x690 net/core/net_namespace.c:580 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 page last free pid 6020 tgid 6019 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2901 selinux_genfs_get_sid security/selinux/hooks.c:1357 [inline] inode_doinit_with_dentry+0xacb/0x12e0 security/selinux/hooks.c:1555 selinux_d_instantiate+0x26/0x30 security/selinux/hooks.c:6523 security_d_instantiate+0x142/0x1a0 security/security.c:4148 d_instantiate+0x5c/0x90 fs/dcache.c:1961 __debugfs_create_file+0x286/0x6b0 fs/debugfs/inode.c:459 debugfs_create_file_full+0x41/0x60 fs/debugfs/inode.c:469 ref_tracker_dir_debugfs+0x19d/0x290 lib/ref_tracker.c:441 ref_tracker_dir_init include/linux/ref_tracker.h:70 [inline] alloc_netdev_mqs+0x314/0x1550 net/core/dev.c:11907 ip6_tnl_init_net+0xf5/0x4d0 net/ipv6/ip6_tunnel.c:2291 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x100/0x390 net/core/net_namespace.c:445 copy_net_ns+0x2f8/0x690 net/core/net_namespace.c:580 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3129 Memory state around the buggy address: ffff8880523f9800: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ffff8880523f9880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880523f9900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880523f9980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880523f9a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================