================================================================== BUG: KASAN: slab-out-of-bounds in __build_skb_around+0x235/0x340 net/core/skbuff.c:294 Write of size 32 at addr ffff8880786242c0 by task syz-executor.2/12425 CPU: 0 PID: 12425 Comm: syz-executor.2 Not tainted 6.1.0-rc8-next-20221207-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x15e/0x45d mm/kasan/report.c:417 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x141/0x190 mm/kasan/generic.c:189 memset+0x24/0x50 mm/kasan/shadow.c:44 __build_skb_around+0x235/0x340 net/core/skbuff.c:294 __build_skb+0x4f/0x60 net/core/skbuff.c:328 build_skb+0x22/0x280 net/core/skbuff.c:340 bpf_prog_test_run_skb+0x343/0x1e10 net/bpf/test_run.c:1131 bpf_prog_test_run kernel/bpf/syscall.c:3644 [inline] __sys_bpf+0x1599/0x4ff0 kernel/bpf/syscall.c:4997 __do_sys_bpf kernel/bpf/syscall.c:5083 [inline] __se_sys_bpf kernel/bpf/syscall.c:5081 [inline] __x64_sys_bpf+0x79/0xc0 kernel/bpf/syscall.c:5081 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f31a988c0d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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:00007f31aa5f8168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f31a99abf80 RCX: 00007f31a988c0d9 RDX: 0000000000000048 RSI: 0000000020000180 RDI: 000000000000000a RBP: 00007f31a98e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd0904a97f R14: 00007f31aa5f8300 R15: 0000000000022000 Allocated by task 12425: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:968 [inline] __kmalloc+0x5a/0xd0 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] bpf_test_init.isra.0+0xa5/0x150 net/bpf/test_run.c:778 bpf_prog_test_run_skb+0x22e/0x1e10 net/bpf/test_run.c:1097 bpf_prog_test_run kernel/bpf/syscall.c:3644 [inline] __sys_bpf+0x1599/0x4ff0 kernel/bpf/syscall.c:4997 __do_sys_bpf kernel/bpf/syscall.c:5083 [inline] __se_sys_bpf kernel/bpf/syscall.c:5081 [inline] __x64_sys_bpf+0x79/0xc0 kernel/bpf/syscall.c:5081 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 kvfree_call_rcu+0x78/0x8f0 kernel/rcu/tree.c:3374 neigh_destroy+0x435/0x640 net/core/neighbour.c:931 neigh_release include/net/neighbour.h:449 [inline] neigh_cleanup_and_release+0x271/0x3d0 net/core/neighbour.c:103 neigh_flush_dev+0x4e7/0x820 net/core/neighbour.c:411 __neigh_ifdown.isra.0+0x54/0x400 net/core/neighbour.c:428 neigh_ifdown+0x1f/0x30 net/core/neighbour.c:446 rt6_disable_ip+0x795/0xa00 net/ipv6/route.c:4901 addrconf_ifdown.isra.0+0x11a/0x1920 net/ipv6/addrconf.c:3750 addrconf_notify+0x104/0x1c80 net/ipv6/addrconf.c:3673 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline] call_netdevice_notifiers net/core/dev.c:1996 [inline] __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571 dev_change_flags+0x11b/0x170 net/core/dev.c:8607 do_setlink+0x9f1/0x3bb0 net/core/rtnetlink.c:2827 rtnl_group_changelink net/core/rtnetlink.c:3344 [inline] __rtnl_newlink+0xb90/0x1840 net/core/rtnetlink.c:3600 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3637 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6141 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1356 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1932 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888078624000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 704 bytes inside of 1024-byte region [ffff888078624000, ffff888078624400) The buggy address belongs to the physical page: page:ffffea0001e18800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888078622000 pfn:0x78620 head:ffffea0001e18800 order:3 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012441dc0 ffffea0001e4e200 dead000000000002 raw: ffff888078622000 0000000080100008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5067, tgid 5063 (syz-fuzzer), ts 342235380283, free_ts 342234386191 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x119c/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x350 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x1a4/0x430 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc_node_track_caller+0x4b/0xc0 mm/slab_common.c:988 kmalloc_reserve net/core/skbuff.c:438 [inline] __alloc_skb+0xe9/0x310 net/core/skbuff.c:511 alloc_skb include/linux/skbuff.h:1269 [inline] __tcp_send_ack.part.0+0x67/0x760 net/ipv4/tcp_output.c:3957 __tcp_send_ack net/ipv4/tcp_output.c:3989 [inline] tcp_send_ack+0x81/0xa0 net/ipv4/tcp_output.c:3989 __tcp_cleanup_rbuf+0x356/0x470 net/ipv4/tcp.c:1617 tcp_recvmsg_locked+0x72c/0x22b0 net/ipv4/tcp.c:2649 tcp_recvmsg+0x117/0x620 net/ipv4/tcp.c:2679 inet_recvmsg+0x114/0x5e0 net/ipv4/af_inet.c:861 sock_recvmsg_nosec net/socket.c:995 [inline] sock_recvmsg net/socket.c:1013 [inline] sock_recvmsg net/socket.c:1009 [inline] sock_read_iter+0x348/0x480 net/socket.c:1086 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1446 [inline] free_pcp_prepare+0x65c/0xc00 mm/page_alloc.c:1496 free_unref_page_prepare mm/page_alloc.c:3369 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3464 skb_free_frag include/linux/skbuff.h:3192 [inline] skb_free_head+0x96/0x110 net/core/skbuff.c:766 skb_release_data+0x5f4/0x870 net/core/skbuff.c:797 skb_release_all net/core/skbuff.c:862 [inline] __kfree_skb net/core/skbuff.c:876 [inline] skb_attempt_defer_free+0x309/0x3e0 net/core/skbuff.c:6651 tcp_eat_recv_skb net/ipv4/tcp.c:1638 [inline] tcp_recvmsg_locked+0x124e/0x22b0 net/ipv4/tcp.c:2633 tcp_recvmsg+0x117/0x620 net/ipv4/tcp.c:2679 inet_recvmsg+0x114/0x5e0 net/ipv4/af_inet.c:861 sock_recvmsg_nosec net/socket.c:995 [inline] sock_recvmsg net/socket.c:1013 [inline] sock_recvmsg net/socket.c:1009 [inline] sock_read_iter+0x348/0x480 net/socket.c:1086 call_read_iter include/linux/fs.h:2180 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x87b/0x9e0 fs/read_write.c:470 ksys_read+0x1ec/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888078624180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888078624200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888078624280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888078624300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888078624380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================