2014-04-11 02:04:07

by wangxiaoming321

[permalink] [raw]
Subject: [PATCH] net: ipv4: current group_info should be put after using.

There is a memory leak in ping when call ping in dumpstate.
Current group_info had been got in ping_init_sock and group_info->usage
increased. But the usage hasn't decreased.
This will make group_info never freed and cause memory leak.

unreferenced object 0xcd0e8840 (size 192):
comm "dumpstate", pid 7583, jiffies 78360 (age 91.810s)
hex dump (first 32 bytes):
02 00 00 00 06 00 00 00 01 00 00 00 ef 03 00 00 ................
f1 03 00 00 f7 03 00 00 04 04 00 00 bb 0b 00 00 ................
backtrace:
[<c1a6bbfc>] kmemleak_alloc+0x3c/0xa0
[<c1320457>] __kmalloc+0xe7/0x1d0
[<c1267c04>] groups_alloc+0x34/0xb0
[<c1267e5c>] SyS_setgroups+0x3c/0xf0
[<c1a864a8>] syscall_call+0x7/0xb
[<ffffffff>] 0xffffffff

Signed-off-by: Chuansheng Liu <[email protected]>
Signed-off-by: Zhang Dongxing <[email protected]>
Signed-off-by: xiaoming wang <[email protected]>
---
net/ipv4/ping.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index f4b19e5..2af7b1f 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -255,23 +255,28 @@ int ping_init_sock(struct sock *sk)
struct group_info *group_info = get_current_groups();
int i, j, count = group_info->ngroups;
kgid_t low, high;
+ int ret = 0;

inet_get_ping_group_range_net(net, &low, &high);
if (gid_lte(low, group) && gid_lte(group, high))
- return 0;
+ goto EXIT;

for (i = 0; i < group_info->nblocks; i++) {
int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
for (j = 0; j < cp_count; j++) {
kgid_t gid = group_info->blocks[i][j];
if (gid_lte(low, gid) && gid_lte(gid, high))
- return 0;
+ goto EXIT;
}

count -= cp_count;
}

- return -EACCES;
+ ret = -EACCES;
+
+EXIT:
+ put_group_info(group_info);
+ return ret;
}
EXPORT_SYMBOL_GPL(ping_init_sock);

--
1.7.1


2014-04-11 03:11:49

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] net: ipv4: current group_info should be put after using.

From: "Wang, Xiaoming" <[email protected]>
Date: Fri, 11 Apr 2014 12:10:38 -0400

> +EXIT:

Do not use all CAPS names for local labels.

Make the label, in lower case, say something about
what state needs to be released at that point.

Something like "out_release_group:"