[PATCH 5.3 137/166] nfc: fix memory leak in llcp_sock_bind()

Greg Kroah-Hartman
2019-10-06T17:55:02Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit a0c2dc1fe63e2869b74c1c7f6a81d1745c8a695d ]

sysbot reported a memory leak after a bind() has failed.

While we are at it, abort the operation if kmemdup() has failed.

BUG: memory leak
unreferenced object 0xffff888105d83ec0 (size 32):
comm "syz-executor067", pid 7207, jiffies 4294956228 (age 19.430s)
hex dump (first 32 bytes):
00 69 6c 65 20 72 65 61 64 00 6e 65 74 3a 5b 34 .ile read.net:[4
30 32 36 35 33 33 30 39 37 5d 00 00 00 00 00 00 026533097]......
backtrace:
[<0000000036bac473>] kmemleak_alloc_recursive /./include/linux/kmemleak.h:43 [inline]
[<0000000036bac473>] slab_post_alloc_hook /mm/slab.h:522 [inline]
[<0000000036bac473>] slab_alloc /mm/slab.c:3319 [inline]
[<0000000036bac473>] __do_kmalloc /mm/slab.c:3653 [inline]
[<0000000036bac473>] __kmalloc_track_caller+0x169/0x2d0 /mm/slab.c:3670
[<000000000cd39d07>] kmemdup+0x27/0x60 /mm/util.c:120
[<000000008e57e5fc>] kmemdup /./include/linux/string.h:432 [inline]
[<000000008e57e5fc>] llcp_sock_bind+0x1b3/0x230 /net/nfc/llcp_sock.c:107
[<000000009cb0b5d3>] __sys_bind+0x11c/0x140 /net/socket.c:1647
[<00000000492c3bbc>] __do_sys_bind /net/socket.c:1658 [inline]
[<00000000492c3bbc>] __se_sys_bind /net/socket.c:1656 [inline]
[<00000000492c3bbc>] __x64_sys_bind+0x1e/0x30 /net/socket.c:1656
[<0000000008704b2a>] do_syscall_64+0x76/0x1a0 /arch/x86/entry/common.c:296
[<000000009f4c57a4>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 30cc4587659e ("NFC: Move LLCP code to the NFC top level diirectory")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/nfc/llcp_sock.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -107,9 +107,14 @@ static int llcp_sock_bind(struct socket
llcp_sock->service_name = kmemdup(llcp_addr.service_name,
llcp_sock->service_name_len,
GFP_KERNEL);
-
+ if (!llcp_sock->service_name) {
+ ret = -ENOMEM;
+ goto put_dev;
+ }
llcp_sock->ssap = nfc_llcp_get_sdp_ssap(local, llcp_sock);
if (llcp_sock->ssap == LLCP_SAP_MAX) {
+ kfree(llcp_sock->service_name);
+ llcp_sock->service_name = NULL;
ret = -EADDRINUSE;
goto put_dev;
}