================================================================== BUG: KASAN: use-after-free in decode_session6+0xe7c/0x1580 net/xfrm/xfrm_policy.c:3393 Read of size 1 at addr ffff8880133ca6ff by task syz-fuzzer/8452 CPU: 1 PID: 8452 Comm: syz-fuzzer Not tainted 5.11.0-rc4-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 decode_session6+0xe7c/0x1580 net/xfrm/xfrm_policy.c:3393 __xfrm_decode_session+0x50/0xb0 net/xfrm/xfrm_policy.c:3485 xfrm_decode_session include/net/xfrm.h:1137 [inline] vti_tunnel_xmit+0x264/0x1980 net/ipv4/ip_vti.c:292 __netdev_start_xmit include/linux/netdevice.h:4776 [inline] netdev_start_xmit include/linux/netdevice.h:4790 [inline] xmit_one net/core/dev.c:3574 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3590 sch_direct_xmit+0x2e1/0xbd0 net/sched/sch_generic.c:313 qdisc_restart net/sched/sch_generic.c:376 [inline] __qdisc_run+0x4ba/0x15f0 net/sched/sch_generic.c:384 __dev_xmit_skb net/core/dev.c:3813 [inline] __dev_queue_xmit+0x1a30/0x2dd0 net/core/dev.c:4119 neigh_connected_output+0x380/0x4c0 net/core/neighbour.c:1520 neigh_output include/net/neighbour.h:510 [inline] ip6_finish_output2+0x6b8/0x16c0 net/ipv6/ip6_output.c:117 __ip6_finish_output net/ipv6/ip6_output.c:182 [inline] __ip6_finish_output+0x4c1/0xe10 net/ipv6/ip6_output.c:161 ip6_finish_output+0x35/0x200 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip6_output+0x1db/0x520 net/ipv6/ip6_output.c:215 dst_output include/net/dst.h:441 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ndisc_send_skb+0xa90/0x1750 net/ipv6/ndisc.c:508 ndisc_send_rs+0x12e/0x700 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3875 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417 expire_timers kernel/time/timer.c:1462 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744 __do_softirq+0x2bc/0xa29 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 RIP: 0033:0x41f86d Code: 00 ff c6 0f b6 3b 49 89 cb 89 f1 41 89 fc d3 ef 49 83 fb 08 74 0a 0f ba e7 04 0f 83 c2 00 00 00 41 0f a3 cc 73 b8 4b 8d 3c 0b <48> 8b 3f 48 85 ff 74 ac 49 89 fc 4c 29 cf 48 39 d7 72 a1 48 89 5c RSP: 002b:000000c000039ea8 EFLAGS: 00000203 RAX: 0000000000203000 RBX: 00007efe936cf05b RCX: 0000000000000003 RDX: 0000000000000400 RSI: 0000000000000003 RDI: 000000c0008a0b78 RBP: 000000c000039f28 R08: 00007efe93889fff R09: 000000c0008a0800 R10: 000000c00001d698 R11: 0000000000000378 R12: 00000000000000fa R13: 000000c000000c00 R14: 0000000000b356ca R15: 0000000000000000 Allocated by task 9788: 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:209 [inline] slab_post_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2891 [inline] __kmalloc_node_track_caller+0x1e0/0x3f0 mm/slub.c:4495 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0xae/0x5a0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1099 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:513 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:570 [inline] nsim_dev_trap_report_work+0x2ac/0xbd0 drivers/net/netdevsim/dev.c:611 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 9788: 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:192 [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] kfree+0xdb/0x3b0 mm/slub.c:4124 skb_free_head net/core/skbuff.c:604 [inline] skb_release_data+0x6d9/0x910 net/core/skbuff.c:624 skb_release_all net/core/skbuff.c:678 [inline] __kfree_skb net/core/skbuff.c:692 [inline] consume_skb net/core/skbuff.c:848 [inline] consume_skb+0xc2/0x160 net/core/skbuff.c:842 nsim_dev_trap_report drivers/net/netdevsim/dev.c:586 [inline] nsim_dev_trap_report_work+0x86f/0xbd0 drivers/net/netdevsim/dev.c:611 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 ffff8880133ca000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1791 bytes inside of 4096-byte region [ffff8880133ca000, ffff8880133cb000) The buggy address belongs to the page: page:00000000d4ee6ace refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x133c8 head:00000000d4ee6ace order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010042140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880133ca580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880133ca600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880133ca680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880133ca700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880133ca780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================