================================================================== BUG: KASAN: slab-out-of-bounds in css_task_iter_advance+0x49b/0x540 kernel/cgroup/cgroup.c:4507 Read of size 4 at addr ffff888095288fdc by task syz-executor.4/19536 CPU: 0 PID: 19536 Comm: syz-executor.4 Not tainted 5.2.0-rc3-next-20190607 #11 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 css_task_iter_advance+0x49b/0x540 kernel/cgroup/cgroup.c:4507 css_task_iter_start+0x18b/0x230 kernel/cgroup/cgroup.c:4543 mem_cgroup_scan_tasks+0xaf/0x180 mm/memcontrol.c:1167 select_bad_process mm/oom_kill.c:374 [inline] out_of_memory mm/oom_kill.c:1088 [inline] out_of_memory+0x6b2/0x1280 mm/oom_kill.c:1035 mem_cgroup_out_of_memory+0x1ca/0x230 mm/memcontrol.c:1573 mem_cgroup_oom mm/memcontrol.c:1905 [inline] try_charge+0xfbe/0x1480 mm/memcontrol.c:2468 mem_cgroup_charge_skmem+0x12f/0x280 mm/memcontrol.c:6452 __sk_mem_raise_allocated+0x555/0x1380 net/core/sock.c:2477 __sk_mem_schedule+0x6d/0xe0 net/core/sock.c:2562 sk_wmem_schedule include/net/sock.h:1413 [inline] tcp_sendmsg_locked+0x1993/0x3920 net/ipv4/tcp.c:1306 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1415 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:665 __sys_sendto+0x262/0x380 net/socket.c:1958 __do_sys_sendto net/socket.c:1970 [inline] __se_sys_sendto net/socket.c:1966 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1966 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe45a720c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459279 RDX: fffffffffffffdce RSI: 0000000020000040 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: fffffffffffffebf R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe45a7216d4 R13: 00000000004c700b R14: 00000000004dc1c8 R15: 00000000ffffffff Allocated by task 9054: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 kmem_cache_alloc_trace+0x151/0x750 mm/slab.c:3549 kmalloc include/linux/slab.h:547 [inline] kzalloc include/linux/slab.h:742 [inline] fib6_info_alloc+0xb6/0x1b0 net/ipv6/ip6_fib.c:154 ip6_route_info_create+0x2a8/0x1240 net/ipv6/route.c:3299 ip6_route_add+0x27/0xc0 net/ipv6/route.c:3391 addrconf_prefix_route.isra.0+0x358/0x4f0 net/ipv6/addrconf.c:2395 fixup_permanent_addr net/ipv6/addrconf.c:3438 [inline] addrconf_permanent_addr net/ipv6/addrconf.c:3462 [inline] addrconf_notify+0x16c3/0x2370 net/ipv6/addrconf.c:3532 notifier_call_chain+0xc2/0x230 kernel/notifier.c:95 __raw_notifier_call_chain kernel/notifier.c:396 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:403 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1749 call_netdevice_notifiers_extack net/core/dev.c:1761 [inline] call_netdevice_notifiers net/core/dev.c:1775 [inline] __dev_notify_flags+0x121/0x2c0 net/core/dev.c:7588 dev_change_flags+0x10d/0x170 net/core/dev.c:7626 do_setlink+0x1615/0x34e0 net/core/rtnetlink.c:2488 __rtnl_newlink+0xbd8/0x16c0 net/core/rtnetlink.c:3120 rtnl_newlink+0x69/0xa0 net/core/rtnetlink.c:3245 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5214 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2482 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5232 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline] netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1333 netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1922 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:665 __sys_sendto+0x262/0x380 net/socket.c:1958 __do_sys_sendto net/socket.c:1970 [inline] __se_sys_sendto net/socket.c:1966 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1966 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff888095288e00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 220 bytes to the right of 256-byte region [ffff888095288e00, ffff888095288f00) The buggy address belongs to the page: page:ffffea000254a200 refcount:1 mapcount:0 mapping:ffff8880aa4007c0 index:0xffff8880952882c0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00025a2408 ffffea0002489808 ffff8880aa4007c0 raw: ffff8880952882c0 ffff888095288040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888095288e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888095288f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888095288f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888095289000: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff888095289080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================