netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. Disabling bearer ================================================================== BUG: KASAN: use-after-free in tipc_udp_xmit+0xa7d/0xc10 net/tipc/udp_media.c:200 Read of size 8 at addr ffff88805315f660 by task syz-executor.2/24035 CPU: 1 PID: 24035 Comm: syz-executor.2 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 tipc_udp_xmit+0xa7d/0xc10 net/tipc/udp_media.c:200 tipc_udp_send_msg+0x279/0x490 net/tipc/udp_media.c:248 tipc_bearer_xmit_skb+0x15b/0x330 net/tipc/bearer.c:518 tipc_disc_timeout+0x855/0xc90 net/tipc/discover.c:332 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 kernel/locking/spinlock.c:192 Code: c0 98 82 f1 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d 01 31 d8 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 26 1b 28 f9 65 8b 05 9f 8d e8 77 85 c0 74 02 5d RSP: 0018:ffff8880af5ef890 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13e3053 RBX: ffff8880b2862140 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff8880b28629c4 RBP: ffff8880ba12b0c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ba12b0c0 R13: ffff8880500d4000 R14: 0000000000000000 R15: 0000000000000000 finish_lock_switch kernel/sched/core.c:2578 [inline] finish_task_switch+0x146/0x760 kernel/sched/core.c:2678 context_switch kernel/sched/core.c:2831 [inline] __schedule+0x88f/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x2fc/0x5e0 kernel/futex.c:2722 futex_wait+0x1ef/0x610 kernel/futex.c:2837 do_futex+0x268/0x1880 kernel/futex.c:3889 __do_sys_futex kernel/futex.c:3950 [inline] __se_sys_futex+0x28f/0x3b0 kernel/futex.c:3918 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fdce98fc279 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdce8271218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fdce9a0ef88 RCX: 00007fdce98fc279 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdce9a0ef88 RBP: 00007fdce9a0ef80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdce9a0ef8c R13: 00007ffdc32e673f R14: 00007fdce8271300 R15: 0000000000022000 Allocated by task 24030: kmem_cache_alloc+0x122/0x370 mm/slab.c:3559 sock_alloc_inode+0x19/0x250 net/socket.c:244 alloc_inode+0x5d/0x180 fs/inode.c:211 new_inode_pseudo+0x14/0xe0 fs/inode.c:911 sock_alloc+0x3c/0x260 net/socket.c:567 __sock_create+0xba/0x740 net/socket.c:1329 udp_sock_create6+0xd1/0x550 net/ipv6/ip6_udp_tunnel.c:22 udp_sock_create include/net/udp_tunnel.h:61 [inline] tipc_udp_enable+0xb48/0x14d0 net/tipc/udp_media.c:734 tipc_enable_bearer+0x70f/0xbe0 net/tipc/bearer.c:317 __tipc_nl_bearer_enable+0x2e2/0x3d0 net/tipc/bearer.c:916 tipc_nl_bearer_enable+0x1e/0x30 net/tipc/bearer.c:925 genl_family_rcv_msg+0x642/0xc40 net/netlink/genetlink.c:602 genl_rcv_msg+0xbf/0x160 net/netlink/genetlink.c:627 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463 genl_rcv+0x24/0x40 net/netlink/genetlink.c:638 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227 __sys_sendmsg net/socket.c:2265 [inline] __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4387: __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x7f/0x260 mm/slab.c:3765 destroy_inode+0xb9/0x110 fs/inode.c:268 iput_final fs/inode.c:1555 [inline] iput+0x4f1/0x860 fs/inode.c:1581 __sock_release net/socket.c:611 [inline] sock_release+0x174/0x1d0 net/socket.c:619 cleanup_bearer+0x1bb/0x280 net/tipc/udp_media.c:775 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff88805315f640 which belongs to the cache sock_inode_cache of size 992 The buggy address is located 32 bytes inside of 992-byte region [ffff88805315f640, ffff88805315fa20) The buggy address belongs to the page: page:ffffea00014c57c0 count:1 mapcount:0 mapping:ffff8880b5b96780 index:0xffff88805315fffd flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffffea000139f048 ffffea00014c5788 ffff8880b5b96780 raw: ffff88805315fffd ffff88805315f1c0 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805315f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805315f580: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805315f600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff88805315f680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805315f700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 5 bytes skipped: 0: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 7: fc ff df a: 48 c1 e8 03 shr $0x3,%rax e: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) 12: 75 31 jne 0x45 14: 48 83 3d 01 31 d8 01 cmpq $0x0,0x1d83101(%rip) # 0x1d8311d 1b: 00 1c: 74 25 je 0x43 1e: fb sti 1f: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) * 25: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2a: e8 26 1b 28 f9 callq 0xf9281b55 2f: 65 8b 05 9f 8d e8 77 mov %gs:0x77e88d9f(%rip),%eax # 0x77e88dd5 36: 85 c0 test %eax,%eax 38: 74 02 je 0x3c 3a: 5d pop %rbp