================================================================== BUG: KASAN: slab-out-of-bounds in ip_icmp_error+0x52a/0x5a0 net/ipv4/ip_sockglue.c:404 Read of size 1 at addr ffff8880940077ff by task ksoftirqd/0/9 CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.7.0-rc7-next-20200526-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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 ip_icmp_error+0x52a/0x5a0 net/ipv4/ip_sockglue.c:404 tcp_v4_err+0x99e/0x1ce0 net/ipv4/tcp_ipv4.c:576 icmp_socket_deliver+0x1e1/0x360 net/ipv4/icmp.c:803 icmp_unreach+0x33b/0xab0 net/ipv4/icmp.c:920 icmp_rcv+0xee6/0x15f0 net/ipv4/icmp.c:1102 ip_protocol_deliver_rcu+0x57/0x880 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x220/0x360 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_local_deliver+0x1c8/0x4e0 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:441 [inline] ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:428 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_rcv+0xd0/0x3c0 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5268 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5382 process_backlog+0x21e/0x7a0 net/core/dev.c:6214 napi_poll net/core/dev.c:6659 [inline] net_rx_action+0x4e1/0x10d0 net/core/dev.c:6727 __do_softirq+0x268/0x9ee kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:604 [inline] run_ksoftirqd+0x89/0x100 kernel/softirq.c:596 smpboot_thread_fn+0x653/0x9e0 kernel/smpboot.c:165 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:350 Allocated by task 6798: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:494 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:467 __kmalloc_reserve.isra.0+0x39/0xe0 net/core/skbuff.c:142 __alloc_skb+0xef/0x5a0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] nlmsg_new include/net/netlink.h:940 [inline] rtmsg_ifinfo_build_skb+0x72/0x1a0 net/core/rtnetlink.c:3702 rtmsg_ifinfo_event.part.0+0x49/0xe0 net/core/rtnetlink.c:3738 rtmsg_ifinfo_event net/core/rtnetlink.c:3749 [inline] rtmsg_ifinfo+0x7f/0xa0 net/core/rtnetlink.c:3747 register_netdevice+0xe64/0x10b0 net/core/dev.c:9537 nsim_create+0x1fb/0x2a0 drivers/net/netdevsim/netdev.c:309 __nsim_dev_port_add+0x31d/0x600 drivers/net/netdevsim/dev.c:907 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:956 [inline] nsim_dev_probe+0xbb9/0xea0 drivers/net/netdevsim/dev.c:1083 really_probe+0x281/0x6d0 drivers/base/dd.c:525 driver_probe_device+0xfe/0x1d0 drivers/base/dd.c:701 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:807 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431 __device_attach+0x21a/0x360 drivers/base/dd.c:873 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xaf1/0x1900 drivers/base/core.c:2662 nsim_bus_dev_new drivers/net/netdevsim/bus.c:336 [inline] new_device_store+0x373/0x5c0 drivers/net/netdevsim/bus.c:215 bus_attr_store+0x72/0xa0 drivers/base/bus.c:122 sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:138 kernfs_fop_write+0x268/0x490 fs/kernfs/file.c:315 __vfs_write+0x76/0x100 fs/read_write.c:495 vfs_write+0x268/0x5d0 fs/read_write.c:559 ksys_write+0x12d/0x250 fs/read_write.c:612 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:353 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 6798: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 skb_free_head+0x8b/0xa0 net/core/skbuff.c:590 pskb_expand_head+0x2cd/0x10b0 net/core/skbuff.c:1660 netlink_trim+0x1ea/0x240 net/netlink/af_netlink.c:1285 netlink_broadcast_filtered+0x5f/0xd40 net/netlink/af_netlink.c:1490 netlink_broadcast net/netlink/af_netlink.c:1535 [inline] nlmsg_multicast include/net/netlink.h:1020 [inline] nlmsg_notify+0x90/0x250 net/netlink/af_netlink.c:2512 rtnl_notify net/core/rtnetlink.c:737 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3726 [inline] rtmsg_ifinfo_event.part.0+0xb6/0xe0 net/core/rtnetlink.c:3741 rtmsg_ifinfo_event net/core/rtnetlink.c:3749 [inline] rtmsg_ifinfo+0x7f/0xa0 net/core/rtnetlink.c:3747 register_netdevice+0xe64/0x10b0 net/core/dev.c:9537 nsim_create+0x1fb/0x2a0 drivers/net/netdevsim/netdev.c:309 __nsim_dev_port_add+0x31d/0x600 drivers/net/netdevsim/dev.c:907 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:956 [inline] nsim_dev_probe+0xbb9/0xea0 drivers/net/netdevsim/dev.c:1083 really_probe+0x281/0x6d0 drivers/base/dd.c:525 driver_probe_device+0xfe/0x1d0 drivers/base/dd.c:701 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:807 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431 __device_attach+0x21a/0x360 drivers/base/dd.c:873 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xaf1/0x1900 drivers/base/core.c:2662 nsim_bus_dev_new drivers/net/netdevsim/bus.c:336 [inline] new_device_store+0x373/0x5c0 drivers/net/netdevsim/bus.c:215 bus_attr_store+0x72/0xa0 drivers/base/bus.c:122 sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:138 kernfs_fop_write+0x268/0x490 fs/kernfs/file.c:315 __vfs_write+0x76/0x100 fs/read_write.c:495 vfs_write+0x268/0x5d0 fs/read_write.c:559 ksys_write+0x12d/0x250 fs/read_write.c:612 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:353 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888094006000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2047 bytes to the right of 4096-byte region [ffff888094006000, ffff888094007000) The buggy address belongs to the page: page:ffffea0002500180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea0002500180 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0002501d08 ffffea00022e8f88 ffff8880aa002000 raw: 0000000000000000 ffff888094006000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888094007680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888094007700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888094007780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888094007800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888094007880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================