===================================================== BUG: KMSAN: use-after-free in l3mdev_master_ifindex_rcu+0x104/0x200 net/l3mdev/l3mdev.c:24 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-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:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 l3mdev_master_ifindex_rcu+0x104/0x200 net/l3mdev/l3mdev.c:24 ipv6_dev_get_saddr+0x516/0xe10 net/ipv6/addrconf.c:1817 ip6_route_get_saddr include/net/ip6_route.h:144 [inline] ip6_dst_lookup_tail+0x1dee/0x2010 net/ipv6/ip6_output.c:1030 ip6_dst_lookup_flow+0x102/0x250 net/ipv6/ip6_output.c:1153 geneve_get_v6_dst+0x7c2/0xa00 drivers/net/geneve.c:856 geneve6_xmit_skb drivers/net/geneve.c:950 [inline] geneve_xmit+0x5d3/0x2c20 drivers/net/geneve.c:1001 __netdev_start_xmit include/linux/netdevice.h:4524 [inline] netdev_start_xmit include/linux/netdevice.h:4538 [inline] xmit_one net/core/dev.c:3470 [inline] dev_hard_start_xmit+0x531/0xab0 net/core/dev.c:3486 __dev_queue_xmit+0x37de/0x4220 net/core/dev.c:4063 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096 neigh_hh_output include/net/neighbour.h:499 [inline] neigh_output include/net/neighbour.h:508 [inline] ip6_finish_output2+0x2056/0x2640 net/ipv6/ip6_output.c:116 __ip6_finish_output+0x824/0x8e0 net/ipv6/ip6_output.c:142 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] mld_sendpack+0xeba/0x13d0 net/ipv6/mcast.c:1682 mld_send_initial_cr+0x448/0x4c0 net/ipv6/mcast.c:2099 mld_dad_timer_expire+0x4d/0x610 net/ipv6/mcast.c:2118 call_timer_fn+0x218/0x510 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers+0xcff/0x1210 kernel/time/timer.c:1773 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786 __do_softirq+0x311/0x83d kernel/softirq.c:293 invoke_softirq kernel/softirq.c:375 [inline] irq_exit+0x230/0x280 kernel/softirq.c:416 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:546 smp_apic_timer_interrupt+0x48/0x70 arch/x86/kernel/apic/apic.c:1149 apic_timer_interrupt+0x2e/0x40 arch/x86/entry/entry_64.S:834 RIP: 0010:default_idle+0x53/0x90 arch/x86/kernel/process.c:696 Code: c3 f4 c9 f2 44 8b 35 44 c6 bf 01 48 c7 c7 98 87 f7 a3 e8 60 e5 96 f3 83 38 00 75 31 45 85 f6 7e 07 0f 00 2d 67 9f 49 00 fb f4 <65> 8b 35 ce 61 c9 5d c7 03 00 00 00 00 c7 43 08 00 00 00 00 bf ff RSP: 0018:ffffa819c0cbbdf8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff962c0e16b798 RBX: ffff962b2d6f89d0 RCX: ffffe557c7a19580 RDX: ffff962bfe35e798 RSI: 0000000000000000 RDI: ffffffffa3f78798 RBP: ffffa819c0cbbe08 R08: ffffe557c000000f R09: ffff962b2fffb000 R10: 0000000000000004 R11: ffffffffa237c120 R12: ffff962b2d6f8000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff962b2d6f89d0 arch_cpu_idle+0x25/0x30 arch/x86/kernel/process.c:686 default_idle_call kernel/sched/idle.c:94 [inline] cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x26c/0x7b0 kernel/sched/idle.c:269 cpu_startup_entry+0x45/0x50 kernel/sched/idle.c:361 start_secondary+0x389/0x480 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_free+0x6e/0xb0 mm/kmsan/kmsan_hooks.c:107 slab_free_freelist_hook mm/slub.c:1477 [inline] slab_free mm/slub.c:3040 [inline] kfree+0x565/0x30a0 mm/slub.c:3993 __netdev_name_node_alt_destroy net/core/dev.c:322 [inline] netdev_name_node_alt_destroy+0x587/0x690 net/core/dev.c:334 rtnl_alt_ifname net/core/rtnetlink.c:3518 [inline] rtnl_linkprop+0x939/0xc00 net/core/rtnetlink.c:3567 rtnl_dellinkprop+0x9d/0xb0 net/core/rtnetlink.c:3588 rtnetlink_rcv_msg+0x1153/0x1570 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343 ___sys_sendmsg net/socket.c:2397 [inline] __sys_sendmsg+0x451/0x5f0 net/socket.c:2430 __compat_sys_sendmsg net/compat.c:642 [inline] __do_compat_sys_sendmsg net/compat.c:649 [inline] __se_compat_sys_sendmsg net/compat.c:646 [inline] __ia32_compat_sys_sendmsg+0xed/0x130 net/compat.c:646 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 =====================================================