netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. ================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:263 [inline] BUG: KASAN: use-after-free in dev_queue_xmit_nit+0x87e/0xa20 net/core/dev.c:2004 Read of size 8 at addr ffff88808c996cf0 by task syz-executor.3/11782 CPU: 1 PID: 11782 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 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 __read_once_size include/linux/compiler.h:263 [inline] dev_queue_xmit_nit+0x87e/0xa20 net/core/dev.c:2004 xmit_one net/core/dev.c:3252 [inline] dev_hard_start_xmit+0xaa/0x920 net/core/dev.c:3272 sch_direct_xmit+0x2d6/0xf70 net/sched/sch_generic.c:332 qdisc_restart net/sched/sch_generic.c:395 [inline] __qdisc_run+0x4d0/0x1640 net/sched/sch_generic.c:403 qdisc_run include/net/pkt_sched.h:120 [inline] net_tx_action+0x4f3/0xc20 net/core/dev.c:4592 __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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:rcu_read_unlock_special+0x456/0xfc0 kernel/rcu/tree_plugin.h:601 Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 bd 09 00 00 48 83 3d ee 24 a0 08 00 0f 84 37 06 00 00 48 8b 3c 24 57 9d <0f> 1f 44 00 00 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e 41 5f c3 c3 48 RSP: 0018:ffff88808d457138 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13e3051 RBX: 0000000000000000 RCX: 1ffff11013d1612d RDX: dffffc0000000000 RSI: ffff88809e8b0970 RDI: 0000000000000286 RBP: ffff88809e8b0434 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809e8b00c0 R13: ffff88809e8b0436 R14: ffff88809e8b0435 R15: ffffffff89f88280 __rcu_read_unlock+0x158/0x160 kernel/rcu/tree_plugin.h:428 rcu_read_unlock include/linux/rcupdate.h:680 [inline] __ip_queue_xmit+0x93f/0x1c10 net/ipv4/ip_output.c:508 __tcp_transmit_skb+0x1b9c/0x3400 net/ipv4/tcp_output.c:1148 tcp_transmit_skb net/ipv4/tcp_output.c:1164 [inline] __tcp_retransmit_skb+0x7e0/0x26f0 net/ipv4/tcp_output.c:2932 tcp_retransmit_skb+0x2a/0x380 net/ipv4/tcp_output.c:2951 tcp_xmit_retransmit_queue.part.0+0x43c/0x970 net/ipv4/tcp_output.c:3032 tcp_xmit_retransmit_queue+0x57/0x70 net/ipv4/tcp_output.c:2986 tcp_xmit_recovery net/ipv4/tcp_input.c:3557 [inline] tcp_xmit_recovery net/ipv4/tcp_input.c:3543 [inline] tcp_ack+0x2712/0x51d0 net/ipv4/tcp_input.c:3720 tcp_rcv_established+0x66b/0x1ef0 net/ipv4/tcp_input.c:5670 tcp_v4_do_rcv+0x5d6/0x870 net/ipv4/tcp_ipv4.c:1547 sk_backlog_rcv include/net/sock.h:952 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2362 release_sock+0x54/0x1b0 net/core/sock.c:2901 sk_stream_wait_memory+0x536/0xd60 net/core/stream.c:145 tcp_sendmsg_locked+0xd54/0x2f60 net/ipv4/tcp.c:1422 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1462 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 __sys_sendto+0x21a/0x320 net/socket.c:1899 __do_sys_sendto net/socket.c:1911 [inline] __se_sys_sendto net/socket.c:1907 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1907 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff85a30f409 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:00007ff858c84168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007ff85a421f80 RCX: 00007ff85a30f409 RDX: 000000000000fe6a RSI: 00000000200012c0 RDI: 0000000000000004 RBP: 00007ff85a36a367 R08: 0000000000000000 R09: 0000000000000027 R10: 000000000020c49a R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcc640304f R14: 00007ff858c84300 R15: 0000000000022000 Allocated by task 11846: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] sk_prot_alloc+0x1e2/0x2d0 net/core/sock.c:1483 sk_alloc+0x36/0xec0 net/core/sock.c:1537 packet_create+0x117/0x850 net/packet/af_packet.c:3259 __sock_create+0x3d8/0x740 net/socket.c:1365 sock_create net/socket.c:1416 [inline] __sys_socket+0xef/0x200 net/socket.c:1458 __do_sys_socket net/socket.c:1467 [inline] __se_sys_socket net/socket.c:1465 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1465 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 11847: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 sk_prot_free net/core/sock.c:1520 [inline] __sk_destruct+0x684/0x8a0 net/core/sock.c:1602 sk_destruct net/core/sock.c:1617 [inline] __sk_free+0x165/0x3b0 net/core/sock.c:1628 sk_free+0x3b/0x50 net/core/sock.c:1639 sock_put include/net/sock.h:1713 [inline] packet_release+0x890/0xb70 net/packet/af_packet.c:3088 __sock_release+0xcd/0x2a0 net/socket.c:599 sock_close+0x15/0x20 net/socket.c:1214 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbf3/0x2be0 kernel/exit.c:870 do_group_exit+0x125/0x310 kernel/exit.c:967 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808c9964c0 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 2096 bytes inside of 4096-byte region [ffff88808c9964c0, ffff88808c9974c0) The buggy address belongs to the page: page:ffffea0002326580 count:1 mapcount:0 mapping:ffff88813bff0dc0 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0002a2c008 ffffea000263d088 ffff88813bff0dc0 raw: 0000000000000000 ffff88808c9964c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808c996b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808c996c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808c996c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808c996d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808c996d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 7 bytes skipped: 0: df 48 c1 fisttps -0x3f(%rax) 3: e8 03 80 3c 10 callq 0x103c800b 8: 00 0f add %cl,(%rdi) a: 85 bd 09 00 00 48 test %edi,0x48000009(%rbp) 10: 83 3d ee 24 a0 08 00 cmpl $0x0,0x8a024ee(%rip) # 0x8a02505 17: 0f 84 37 06 00 00 je 0x654 1d: 48 8b 3c 24 mov (%rsp),%rdi 21: 57 push %rdi 22: 9d popfq * 23: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 28: 48 83 c4 40 add $0x40,%rsp 2c: 5b pop %rbx 2d: 5d pop %rbp 2e: 41 5c pop %r12 30: 41 5d pop %r13 32: 41 5e pop %r14 34: 41 5f pop %r15 36: c3 retq 37: c3 retq 38: 48 rex.W