lkml.org 
[lkml]   [2022]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.18 087/231] vlan: fix memory leak in vlan_newlink()
    Date
    From: Eric Dumazet <edumazet@google.com>

    [ Upstream commit 72a0b329114b1caa8e69dfa7cdad1dd3c69b8602 ]

    Blamed commit added back a bug I fixed in commit 9bbd917e0bec
    ("vlan: fix memory leak in vlan_dev_set_egress_priority")

    If a memory allocation fails in vlan_changelink() after other allocations
    succeeded, we need to call vlan_dev_free_egress_priority()
    to free all allocated memory because after a failed ->newlink()
    we do not call any methods like ndo_uninit() or dev->priv_destructor().

    In following example, if the allocation for last element 2000:2001 fails,
    we need to free eight prior allocations:

    ip link add link dummy0 dummy0.100 type vlan id 100 \
    egress-qos-map 1:2 2:3 3:4 4:5 5:6 6:7 7:8 8:9 2000:2001

    syzbot report was:

    BUG: memory leak
    unreferenced object 0xffff888117bd1060 (size 32):
    comm "syz-executor408", pid 3759, jiffies 4294956555 (age 34.090s)
    hex dump (first 32 bytes):
    09 00 00 00 00 a0 00 00 00 00 00 00 00 00 00 00 ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
    backtrace:
    [<ffffffff83fc60ad>] kmalloc include/linux/slab.h:600 [inline]
    [<ffffffff83fc60ad>] vlan_dev_set_egress_priority+0xed/0x170 net/8021q/vlan_dev.c:193
    [<ffffffff83fc6628>] vlan_changelink+0x178/0x1d0 net/8021q/vlan_netlink.c:128
    [<ffffffff83fc67c8>] vlan_newlink+0x148/0x260 net/8021q/vlan_netlink.c:185
    [<ffffffff838b1278>] rtnl_newlink_create net/core/rtnetlink.c:3363 [inline]
    [<ffffffff838b1278>] __rtnl_newlink+0xa58/0xdc0 net/core/rtnetlink.c:3580
    [<ffffffff838b1629>] rtnl_newlink+0x49/0x70 net/core/rtnetlink.c:3593
    [<ffffffff838ac66c>] rtnetlink_rcv_msg+0x21c/0x5c0 net/core/rtnetlink.c:6089
    [<ffffffff839f9c37>] netlink_rcv_skb+0x87/0x1d0 net/netlink/af_netlink.c:2501
    [<ffffffff839f8da7>] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
    [<ffffffff839f8da7>] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345
    [<ffffffff839f9266>] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921
    [<ffffffff8384dbf6>] sock_sendmsg_nosec net/socket.c:714 [inline]
    [<ffffffff8384dbf6>] sock_sendmsg+0x56/0x80 net/socket.c:734
    [<ffffffff8384e15c>] ____sys_sendmsg+0x36c/0x390 net/socket.c:2488
    [<ffffffff838523cb>] ___sys_sendmsg+0x8b/0xd0 net/socket.c:2542
    [<ffffffff838525b8>] __sys_sendmsg net/socket.c:2571 [inline]
    [<ffffffff838525b8>] __do_sys_sendmsg net/socket.c:2580 [inline]
    [<ffffffff838525b8>] __se_sys_sendmsg net/socket.c:2578 [inline]
    [<ffffffff838525b8>] __x64_sys_sendmsg+0x78/0xf0 net/socket.c:2578
    [<ffffffff845ad8d5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff845ad8d5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff8460006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

    Fixes: 37aa50c539bc ("vlan: introduce vlan_dev_free_egress_priority")
    Reported-by: syzbot <syzkaller@googlegroups.com>
    Signed-off-by: Eric Dumazet <edumazet@google.com>
    Cc: Xin Long <lucien.xin@gmail.com>
    Reviewed-by: Xin Long <lucien.xin@gmail.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    net/8021q/vlan_netlink.c | 10 +++++++---
    1 file changed, 7 insertions(+), 3 deletions(-)

    diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
    index 53b1955b027f..214532173536 100644
    --- a/net/8021q/vlan_netlink.c
    +++ b/net/8021q/vlan_netlink.c
    @@ -182,10 +182,14 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
    else if (dev->mtu > max_mtu)
    return -EINVAL;

    + /* Note: If this initial vlan_changelink() fails, we need
    + * to call vlan_dev_free_egress_priority() to free memory.
    + */
    err = vlan_changelink(dev, tb, data, extack);
    - if (err)
    - return err;
    - err = register_vlan_dev(dev, extack);
    +
    + if (!err)
    + err = register_vlan_dev(dev, extack);
    +
    if (err)
    vlan_dev_free_egress_priority(dev);
    return err;
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-07-19 15:04    [W:4.221 / U:0.400 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site