Re: memory leak in vhost_net_ioctl

From: syzbot
Date: Thu Jun 13 2019 - 23:08:47 EST

Hello,

syzbot has tested the proposed patch but the reproducer still triggered crash:
memory leak in batadv_tvlv_handler_register

484.626788][ T156] bond0 (unregistering): Releasing backup interface bond_slave_1
Warning: Permanently added '10.128.0.87' (ECDSA) to the list of known hosts.
BUG: memory leak
unreferenced object 0xffff88811d25c4c0 (size 64):
comm "softirq", pid 0, jiffies 4294943668 (age 434.830s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 e0 fc 5b 20 81 88 ff ff ..........[ ....
00 00 00 00 00 00 00 00 20 91 15 83 ff ff ff ff ........ .......
backtrace:
[<000000000045bc9d>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
[<000000000045bc9d>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<000000000045bc9d>] slab_alloc mm/slab.c:3326 [inline]
[<000000000045bc9d>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<00000000197d773e>] kmalloc include/linux/slab.h:547 [inline]
[<00000000197d773e>] kzalloc include/linux/slab.h:742 [inline]
[<00000000197d773e>] batadv_tvlv_handler_register+0xae/0x140 net/batman-adv/tvlv.c:529
[<00000000fa9f11af>] batadv_tt_init+0x78/0x180 net/batman-adv/translation-table.c:4411
[<000000008c50839d>] batadv_mesh_init+0x196/0x230 net/batman-adv/main.c:208
[<000000001c5a74a3>] batadv_softif_init_late+0x1ca/0x220 net/batman-adv/soft-interface.c:861
[<000000004e676cd1>] register_netdevice+0xbf/0x600 net/core/dev.c:8635
[<000000005601497b>] __rtnl_newlink+0xaca/0xb30 net/core/rtnetlink.c:3199
[<00000000ad02cf5e>] rtnl_newlink+0x4e/0x80 net/core/rtnetlink.c:3245
[<00000000eceb53af>] rtnetlink_rcv_msg+0x178/0x4b0 net/core/rtnetlink.c:5214
[<00000000140451f6>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2482
[<00000000237e38f7>] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5232
[<000000000d47c000>] netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline]
[<000000000d47c000>] netlink_unicast+0x1ec/0x2d0 net/netlink/af_netlink.c:1333
[<0000000098503d79>] netlink_sendmsg+0x26a/0x480 net/netlink/af_netlink.c:1922
[<000000009263e868>] sock_sendmsg_nosec net/socket.c:646 [inline]
[<000000009263e868>] sock_sendmsg+0x54/0x70 net/socket.c:665
[<000000007791ad47>] __sys_sendto+0x148/0x1f0 net/socket.c:1958
[<00000000d6f3807d>] __do_sys_sendto net/socket.c:1970 [inline]
[<00000000d6f3807d>] __se_sys_sendto net/socket.c:1966 [inline]
[<00000000d6f3807d>] __x64_sys_sendto+0x2a/0x30 net/socket.c:1966

BUG: memory leak
unreferenced object 0xffff8881024a3340 (size 64):
comm "softirq", pid 0, jiffies 4294943678 (age 434.730s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 e0 2c 66 04 81 88 ff ff .........,f.....
00 00 00 00 00 00 00 00 20 91 15 83 ff ff ff ff ........ .......
backtrace:
[<000000000045bc9d>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
[<000000000045bc9d>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<000000000045bc9d>] slab_alloc mm/slab.c:3326 [inline]
[<000000000045bc9d>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<00000000197d773e>] kmalloc include/linux/slab.h:547 [inline]
[<00000000197d773e>] kzalloc include/linux/slab.h:742 [inline]
[<00000000197d773e>] batadv_tvlv_handler_register+0xae/0x140 net/batman-adv/tvlv.c:529
[<00000000fa9f11af>] batadv_tt_init+0x78/0x180 net/batman-adv/translation-table.c:4411
[<000000008c50839d>] batadv_mesh_init+0x196/0x230 net/batman-adv/main.c:208
[<000000001c5a74a3>] batadv_softif_init_late+0x1ca/0x220 net/batman-adv/soft-interface.c:861
[<000000004e676cd1>] register_netdevice+0xbf/0x600 net/core/dev.c:8635
[<000000005601497b>] __rtnl_newlink+0xaca/0xb30 net/core/rtnetlink.c:3199
[<00000000ad02cf5e>] rtnl_newlink+0x4e/0x80 net/core/rtnetlink.c:3245
[<00000000eceb53af>] rtnetlink_rcv_msg+0x178/0x4b0 net/core/rtnetlink.c:5214
[<00000000140451f6>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2482
[<00000000237e38f7>] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5232
[<000000000d47c000>] netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline]
[<000000000d47c000>] netlink_unicast+0x1ec/0x2d0 net/netlink/af_netlink.c:1333
[<0000000098503d79>] netlink_sendmsg+0x26a/0x480 net/netlink/af_netlink.c:1922
[<000000009263e868>] sock_sendmsg_nosec net/socket.c:646 [inline]
[<000000009263e868>] sock_sendmsg+0x54/0x70 net/socket.c:665
[<000000007791ad47>] __sys_sendto+0x148/0x1f0 net/socket.c:1958
[<00000000d6f3807d>] __do_sys_sendto net/socket.c:1970 [inline]
[<00000000d6f3807d>] __se_sys_sendto net/socket.c:1966 [inline]
[<00000000d6f3807d>] __x64_sys_sendto+0x2a/0x30 net/socket.c:1966

BUG: memory leak
unreferenced object 0xffff888108a71b80 (size 128):
comm "syz-executor.3", pid 7367, jiffies 4294943696 (age 434.550s)
hex dump (first 32 bytes):
f0 f8 bf 02 81 88 ff ff f0 f8 bf 02 81 88 ff ff ................
1a dc 77 da 54 a0 be 41 64 20 e9 56 ff ff ff ff ..w.T..Ad .V....
backtrace:
[<000000000045bc9d>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
[<000000000045bc9d>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<000000000045bc9d>] slab_alloc mm/slab.c:3326 [inline]
[<000000000045bc9d>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<00000000cc6863ae>] kmalloc include/linux/slab.h:547 [inline]
[<00000000cc6863ae>] hsr_create_self_node+0x42/0x150 net/hsr/hsr_framereg.c:84
[<000000000e2bb6b0>] hsr_dev_finalize+0xa4/0x233 net/hsr/hsr_device.c:441
[<000000003b100a4a>] hsr_newlink+0xf3/0x140 net/hsr/hsr_netlink.c:69
[<00000000b5efb0eb>] __rtnl_newlink+0x892/0xb30 net/core/rtnetlink.c:3187
[<00000000ad02cf5e>] rtnl_newlink+0x4e/0x80 net/core/rtnetlink.c:3245
[<00000000eceb53af>] rtnetlink_rcv_msg+0x178/0x4b0 net/core/rtnetlink.c:5214
[<00000000140451f6>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2482
[<00000000237e38f7>] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5232
[<000000000d47c000>] netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline]
[<000000000d47c000>] netlink_unicast+0x1ec/0x2d0 net/netlink/af_netlink.c:1333
[<0000000098503d79>] netlink_sendmsg+0x26a/0x480 net/netlink/af_netlink.c:1922
[<000000009263e868>] sock_sendmsg_nosec net/socket.c:646 [inline]
[<000000009263e868>] sock_sendmsg+0x54/0x70 net/socket.c:665
[<000000007791ad47>] __sys_sendto+0x148/0x1f0 net/socket.c:1958
[<00000000d6f3807d>] __do_sys_sendto net/socket.c:1970 [inline]
[<00000000d6f3807d>] __se_sys_sendto net/socket.c:1966 [inline]
[<00000000d6f3807d>] __x64_sys_sendto+0x2a/0x30 net/socket.c:1966
[<000000003ba31db7>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
[<0000000075c8daad>] entry_SYSCALL_64_after_hwframe+0x44/0xa9



Tested on:

commit: c11fb13a Merge branch 'for-linus' of git://git.kernel.org/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15c8f3b6a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=cb38d33cd06d8d48
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
patch: https://syzkaller.appspot.com/x/patch.diff?x=12477101a00000