Re: [PATCH v2 net] rtnetlink: Fix memory(net_device) leak when ->newlink fails
From: Weilong Chen Date: Tue, 14 Jul 2020 15:32:28 +0800 > Fixes: commit e51fb152318ee6 (rtnetlink: fix a memory leak when ->newlink > fails) As others have pointed out this Fixes: tag is not formatted properly. Please fix this up and resubmit.
Re: [PATCH v2 net] rtnetlink: Fix memory(net_device) leak when ->newlink fails
On 2020/7/14 15:32, Weilong Chen wrote: > When vlan_newlink call register_vlan_dev fails, it might return error > with dev->reg_state = NETREG_UNREGISTERED. The rtnl_newlink should > free the memory. But currently rtnl_newlink only free the memory which > state is NETREG_UNINITIALIZED. > > BUG: memory leak > unreferenced object 0x8881051de000 (size 4096): > comm "syz-executor139", pid 560, jiffies 4294745346 (age 32.445s) > hex dump (first 32 bytes): > 76 6c 61 6e 32 00 00 00 00 00 00 00 00 00 00 00 vlan2... > 00 45 28 03 81 88 ff ff 00 00 00 00 00 00 00 00 .E(. > backtrace: > [<47527e31>] kmalloc_node include/linux/slab.h:578 [inline] > [<47527e31>] kvmalloc_node+0x33/0xd0 mm/util.c:574 > [<2b59e3bc>] kvmalloc include/linux/mm.h:753 [inline] > [<2b59e3bc>] kvzalloc include/linux/mm.h:761 [inline] > [<2b59e3bc>] alloc_netdev_mqs+0x83/0xd90 net/core/dev.c:9929 > [<6076752a>] rtnl_create_link+0x2c0/0xa20 > net/core/rtnetlink.c:3067 > [<572b3be5>] __rtnl_newlink+0xc9c/0x1330 net/core/rtnetlink.c:3329 > [] rtnl_newlink+0x66/0x90 net/core/rtnetlink.c:3397 > [<52c7c0a9>] rtnetlink_rcv_msg+0x540/0x990 > net/core/rtnetlink.c:5460 > [<4b5cb379>] netlink_rcv_skb+0x12b/0x3a0 > net/netlink/af_netlink.c:2469 > [ ] netlink_unicast_kernel net/netlink/af_netlink.c:1303 > [inline] > [ ] netlink_unicast+0x4c6/0x690 > net/netlink/af_netlink.c:1329 > [ ] netlink_sendmsg+0x735/0xcc0 > net/netlink/af_netlink.c:1918 > [<9221ebf7>] sock_sendmsg_nosec net/socket.c:652 [inline] > [<9221ebf7>] sock_sendmsg+0x109/0x140 net/socket.c:672 > [<1c30ffe4>] sys_sendmsg+0x5f5/0x780 net/socket.c:2352 > [ ] ___sys_sendmsg+0x11d/0x1a0 net/socket.c:2406 > [<07297384>] __sys_sendmsg+0xeb/0x1b0 net/socket.c:2439 > [<0eb29b11>] do_syscall_64+0x56/0xa0 arch/x86/entry/common.c:359 > [<6839b4d0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Fixes: commit e51fb152318ee6 (rtnetlink: fix a memory leak when ->newlink > fails) Should be: Fixes: e51fb152318ee6 ("rtnetlink: fix a memory leak when ->newlink fails")
[PATCH v2 net] rtnetlink: Fix memory(net_device) leak when ->newlink fails
When vlan_newlink call register_vlan_dev fails, it might return error with dev->reg_state = NETREG_UNREGISTERED. The rtnl_newlink should free the memory. But currently rtnl_newlink only free the memory which state is NETREG_UNINITIALIZED. BUG: memory leak unreferenced object 0x8881051de000 (size 4096): comm "syz-executor139", pid 560, jiffies 4294745346 (age 32.445s) hex dump (first 32 bytes): 76 6c 61 6e 32 00 00 00 00 00 00 00 00 00 00 00 vlan2... 00 45 28 03 81 88 ff ff 00 00 00 00 00 00 00 00 .E(. backtrace: [<47527e31>] kmalloc_node include/linux/slab.h:578 [inline] [<47527e31>] kvmalloc_node+0x33/0xd0 mm/util.c:574 [<2b59e3bc>] kvmalloc include/linux/mm.h:753 [inline] [<2b59e3bc>] kvzalloc include/linux/mm.h:761 [inline] [<2b59e3bc>] alloc_netdev_mqs+0x83/0xd90 net/core/dev.c:9929 [<6076752a>] rtnl_create_link+0x2c0/0xa20 net/core/rtnetlink.c:3067 [<572b3be5>] __rtnl_newlink+0xc9c/0x1330 net/core/rtnetlink.c:3329 [] rtnl_newlink+0x66/0x90 net/core/rtnetlink.c:3397 [<52c7c0a9>] rtnetlink_rcv_msg+0x540/0x990 net/core/rtnetlink.c:5460 [<4b5cb379>] netlink_rcv_skb+0x12b/0x3a0 net/netlink/af_netlink.c:2469 [ ] netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] [ ] netlink_unicast+0x4c6/0x690 net/netlink/af_netlink.c:1329 [ ] netlink_sendmsg+0x735/0xcc0 net/netlink/af_netlink.c:1918 [<9221ebf7>] sock_sendmsg_nosec net/socket.c:652 [inline] [<9221ebf7>] sock_sendmsg+0x109/0x140 net/socket.c:672 [<1c30ffe4>] sys_sendmsg+0x5f5/0x780 net/socket.c:2352 [ ] ___sys_sendmsg+0x11d/0x1a0 net/socket.c:2406 [<07297384>] __sys_sendmsg+0xeb/0x1b0 net/socket.c:2439 [<0eb29b11>] do_syscall_64+0x56/0xa0 arch/x86/entry/common.c:359 [<6839b4d0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: commit e51fb152318ee6 (rtnetlink: fix a memory leak when ->newlink fails) Cc: David S. Miller Reported-by: Hulk Robot Signed-off-by: Weilong Chen --- net/core/rtnetlink.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 9aedc15736ad..85a4b0101f76 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3343,7 +3343,8 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, */ if (err < 0) { /* If device is not registered at all, free it now */ - if (dev->reg_state == NETREG_UNINITIALIZED) + if (dev->reg_state == NETREG_UNINITIALIZED || + dev->reg_state == NETREG_UNREGISTERED) free_netdev(dev); goto out; } -- 2.17.1
