bisecting fixing commit since 13d2ce42de8cb98ff952f8de6307f896203854c2 building syzkaller on 8f160dd5d603e9cd86705baad260794afa3e5cb3 testing commit 13d2ce42de8cb98ff952f8de6307f896203854c2 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: ebd9c0ad0f470e8c12743442f210bc51b9da275d80d05c5b1574935b94a7abab run #0: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #1: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #2: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #3: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #4: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #5: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #6: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #7: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #8: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #9: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #10: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #11: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #12: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #13: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #14: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #15: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #16: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #17: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #18: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #19: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit testing current HEAD 6db10b4d5efdc38ff06dfdde28dc5477f754b0bd testing commit 6db10b4d5efdc38ff06dfdde28dc5477f754b0bd compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: ba4d94b83441fe3e11af1f9658929ebb3de5d15dc8883cd195ac838d119eb323 run #0: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #1: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #2: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #3: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #4: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #5: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #6: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit run #7: crashed: KASAN: slab-out-of-bounds Read in ipvlan_mac_hash run #8: crashed: KASAN: slab-out-of-bounds Read in ipvlan_queue_xmit run #9: crashed: KASAN: use-after-free Read in ipvlan_queue_xmit revisions tested: 2, total time: 28m34.50528042s (build: 21m5.787957948s, test: 7m1.327259935s) the crash still happens on HEAD commit msg: Linux 4.19.209 crash: KASAN: use-after-free Read in ipvlan_queue_xmit wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 ================================================================== IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready BUG: KASAN: use-after-free in ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:533 [inline] BUG: KASAN: use-after-free in ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:593 [inline] BUG: KASAN: use-after-free in ipvlan_queue_xmit+0x89d/0x1630 drivers/net/ipvlan/ipvlan_core.c:654 Read of size 4 at addr ffff88809727433f by task syz-executor.2/9904 CPU: 0 PID: 9904 Comm: syz-executor.2 Not tainted 4.19.209-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready print_address_description.cold.6+0x9/0x211 mm/kasan/report.c:256 IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:396 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:533 [inline] ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:593 [inline] ipvlan_queue_xmit+0x89d/0x1630 drivers/net/ipvlan/ipvlan_core.c:654 ipvlan_start_xmit+0x4a/0x150 drivers/net/ipvlan/ipvlan_main.c:290 __netdev_start_xmit include/linux/netdevice.h:4349 [inline] netdev_start_xmit include/linux/netdevice.h:4363 [inline] dev_direct_xmit+0x2db/0x620 net/core/dev.c:3905 packet_direct_xmit+0xd6/0x140 net/packet/af_packet.c:246 packet_snd net/packet/af_packet.c:2988 [inline] packet_sendmsg+0x367a/0x6cf0 net/packet/af_packet.c:3013 IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 sock_write_iter+0x215/0x420 net/socket.c:966 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready call_write_iter include/linux/fs.h:1821 [inline] aio_write+0x2e4/0x560 fs/aio.c:1574 wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 __io_submit_one fs/aio.c:1858 [inline] io_submit_one+0x764/0x1db0 fs/aio.c:1909 __do_sys_io_submit fs/aio.c:1953 [inline] __se_sys_io_submit+0x112/0x390 fs/aio.c:1924 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready __x64_sys_io_submit+0x6e/0xb0 fs/aio.c:1924 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465a49 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 bc ff ff ff f7 d8 64 89 01 48 IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready RSP: 002b:00007fc312c03188 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 RAX: ffffffffffffffda RBX: 000000000055bf40 RCX: 0000000000465a49 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 RDX: 0000000020000080 RSI: 0000000000000001 RDI: 00007fc312be2000 RBP: 00000000004af682 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf40 R13: 00007ffef81d44bf R14: 00007fc312c03300 R15: 0000000000022000 Allocated by task 8448: save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:553 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:538 __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node_track_caller+0x50/0x70 mm/slab.c:3703 __kmalloc_reserve.isra.9+0x2c/0xc0 net/core/skbuff.c:137 pskb_expand_head+0x113/0xd80 net/core/skbuff.c:1473 netlink_trim+0x1a7/0x200 net/netlink/af_netlink.c:1302 netlink_broadcast_filtered+0x57/0x900 net/netlink/af_netlink.c:1499 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready netlink_broadcast+0xe/0x10 net/netlink/af_netlink.c:1544 nlmsg_multicast include/net/netlink.h:591 [inline] nlmsg_notify+0x10c/0x140 net/netlink/af_netlink.c:2500 rtnl_notify net/core/rtnetlink.c:736 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3377 [inline] rtmsg_ifinfo_event.part.14+0x7f/0xb0 net/core/rtnetlink.c:3392 rtmsg_ifinfo_event net/core/rtnetlink.c:3400 [inline] rtmsg_ifinfo+0x4e/0x70 net/core/rtnetlink.c:3398 dev_open net/core/dev.c:1441 [inline] dev_open+0xe3/0x110 net/core/dev.c:1430 bond_enslave+0x8ac/0x4c60 drivers/net/bonding/bond_main.c:1561 do_set_master net/core/rtnetlink.c:2321 [inline] do_set_master+0x171/0x200 net/core/rtnetlink.c:2295 do_setlink+0x94c/0x2ec0 net/core/rtnetlink.c:2455 rtnl_newlink+0x975/0x1360 net/core/rtnetlink.c:3077 rtnetlink_rcv_msg+0x34f/0x950 net/core/rtnetlink.c:4782 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 __sys_sendto+0x1f2/0x2e0 net/socket.c:1899 __do_sys_sendto net/socket.c:1911 [inline] __se_sys_sendto net/socket.c:1907 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1907 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8448: save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x13c/0x220 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kfree+0xcf/0x220 mm/slab.c:3822 skb_free_head+0x74/0x90 net/core/skbuff.c:563 skb_release_data+0x513/0x760 net/core/skbuff.c:583 skb_release_all+0x3d/0x50 net/core/skbuff.c:640 __kfree_skb net/core/skbuff.c:654 [inline] consume_skb+0x93/0x270 net/core/skbuff.c:714 netlink_broadcast_filtered+0x28e/0x900 net/netlink/af_netlink.c:1522 netlink_broadcast+0xe/0x10 net/netlink/af_netlink.c:1544 nlmsg_multicast include/net/netlink.h:591 [inline] nlmsg_notify+0x10c/0x140 net/netlink/af_netlink.c:2500 rtnl_notify net/core/rtnetlink.c:736 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3377 [inline] rtmsg_ifinfo_event.part.14+0x7f/0xb0 net/core/rtnetlink.c:3392 rtmsg_ifinfo_event net/core/rtnetlink.c:3400 [inline] rtmsg_ifinfo+0x4e/0x70 net/core/rtnetlink.c:3398 dev_open net/core/dev.c:1441 [inline] dev_open+0xe3/0x110 net/core/dev.c:1430 bond_enslave+0x8ac/0x4c60 drivers/net/bonding/bond_main.c:1561 do_set_master net/core/rtnetlink.c:2321 [inline] do_set_master+0x171/0x200 net/core/rtnetlink.c:2295 do_setlink+0x94c/0x2ec0 net/core/rtnetlink.c:2455 rtnl_newlink+0x975/0x1360 net/core/rtnetlink.c:3077 rtnetlink_rcv_msg+0x34f/0x950 net/core/rtnetlink.c:4782 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 __sys_sendto+0x1f2/0x2e0 net/socket.c:1899 __do_sys_sendto net/socket.c:1911 [inline] __se_sys_sendto net/socket.c:1907 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1907 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888097274240 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 255 bytes inside of 2048-byte region [ffff888097274240, ffff888097274a40) The buggy address belongs to the page: page:ffffea00025c9d00 count:1 mapcount:0 mapping:ffff88813bff6c40 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0002897a88 ffffea0002bfc288 ffff88813bff6c40 raw: 0000000000000000 ffff888097274240 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888097274200: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff888097274280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888097274300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888097274380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888097274400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================