[PATCH net v2] calipso: Fix memory leak in netlbl_calipso_add_pass()

[Paul Moore]

On Thu, Nov 23, 2023 at 4:25 AM Gavrilov Ilia <Ilia.Gavrilov at infotecs.ru> wrote:
>
> If IPv6 support is disabled at boot (ipv6.disable=1),
> the calipso_init() -> netlbl_calipso_ops_register() function isn't called,
> and the netlbl_calipso_ops_get() function always returns NULL.
> In this case, the netlbl_calipso_add_pass() function allocates memory
> for the doi_def variable but doesn't free it with the calipso_doi_free().
>
> BUG: memory leak
> unreferenced object 0xffff888011d68180 (size 64):
>   comm "syz-executor.1", pid 10746, jiffies 4295410986 (age 17.928s)
>   hex dump (first 32 bytes):
>     00 00 00 00 02 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 00  ................
>   backtrace:
>     [<00000000730d8770>] kmalloc include/linux/slab.h:552 [inline]
>     [<00000000730d8770>] netlbl_calipso_add_pass net/netlabel/netlabel_calipso.c:76 [inline]
>     [<00000000730d8770>] netlbl_calipso_add+0x22e/0x4f0 net/netlabel/netlabel_calipso.c:111
>     [<0000000002e662c0>] genl_family_rcv_msg_doit+0x22f/0x330 net/netlink/genetlink.c:739
>     [<00000000a08d6d74>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
>     [<00000000a08d6d74>] genl_rcv_msg+0x341/0x5a0 net/netlink/genetlink.c:800
>     [<0000000098399a97>] netlink_rcv_skb+0x14d/0x440 net/netlink/af_netlink.c:2515
>     [<00000000ff7db83b>] genl_rcv+0x29/0x40 net/netlink/genetlink.c:811
>     [<000000000cf53b8c>] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
>     [<000000000cf53b8c>] netlink_unicast+0x54b/0x800 net/netlink/af_netlink.c:1339
>     [<00000000d78cd38b>] netlink_sendmsg+0x90a/0xdf0 net/netlink/af_netlink.c:1934
>     [<000000008328a57f>] sock_sendmsg_nosec net/socket.c:651 [inline]
>     [<000000008328a57f>] sock_sendmsg+0x157/0x190 net/socket.c:671
>     [<000000007b65a1b5>] ____sys_sendmsg+0x712/0x870 net/socket.c:2342
>     [<0000000083da800e>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2396
>     [<000000004a9b827f>] __sys_sendmsg+0xea/0x1b0 net/socket.c:2429
>     [<0000000061b64d3a>] do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46
>     [<00000000a1265347>] entry_SYSCALL_64_after_hwframe+0x61/0xc6
>
> Found by InfoTeCS on behalf of Linux Verification Center
> (linuxtesting.org) with Syzkaller
>
> Fixes: cb72d38211ea ("netlabel: Initial support for the CALIPSO netlink protocol.")
> Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov at infotecs.ru>
> ---
> v2:
>   - return the error code in netlbl_calipso_add() if the variable calipso_hops is NULL
> v1: https://lore.kernel.org/all/20231122135242.2779058-1-Ilia.Gavrilov@infotecs.ru/
>
>  net/netlabel/netlabel_calipso.c | 49 +++++++++++++++++----------------
>  1 file changed, 26 insertions(+), 23 deletions(-)

This looks good to me, thanks!

Acked-by: Paul Moore <paul at paul-moore.com>

-- 
paul-moore.com