Re: [PATCH v2] net: mac802154: Fix general protection fault

[Stefan Schmidt <stefan@datenfreihafen.org>]

Hello.

On 04.03.21 16:21, Pavel Skripkin wrote:
> syzbot found general protection fault in crypto_destroy_tfm()[1].
> It was caused by wrong clean up loop in llsec_key_alloc().
> If one of the tfm array members is in IS_ERR() range it will
> cause general protection fault in clean up function [1].
> 
> Call Trace:
>   crypto_free_aead include/crypto/aead.h:191 [inline] [1]
>   llsec_key_alloc net/mac802154/llsec.c:156 [inline]
>   mac802154_llsec_key_add+0x9e0/0xcc0 net/mac802154/llsec.c:249
>   ieee802154_add_llsec_key+0x56/0x80 net/mac802154/cfg.c:338
>   rdev_add_llsec_key net/ieee802154/rdev-ops.h:260 [inline]
>   nl802154_add_llsec_key+0x3d3/0x560 net/ieee802154/nl802154.c:1584
>   genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:739
>   genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
>   genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:800
>   netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
>   genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
>   netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
>   netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
>   netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
>   sock_sendmsg_nosec net/socket.c:654 [inline]
>   sock_sendmsg+0xcf/0x120 net/socket.c:674
>   ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
>   ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
>   __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
>   do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>   entry_SYSCALL_64_after_hwframe+0x44/0xae
> 
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> Reported-by: syzbot+9ec037722d2603a9f52e@syzkaller.appspotmail.com
> Change-Id: I29f7ac641a039096d63d1e6070bb32cb5a3beb07
> ---
>   net/mac802154/llsec.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/mac802154/llsec.c b/net/mac802154/llsec.c
> index 585d33144c33..55550ead2ced 100644
> --- a/net/mac802154/llsec.c
> +++ b/net/mac802154/llsec.c
> @@ -152,7 +152,7 @@ llsec_key_alloc(const struct ieee802154_llsec_key *template)
>   	crypto_free_sync_skcipher(key->tfm0);
>   err_tfm:
>   	for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
> -		if (key->tfm[i])
> +		if (!IS_ERR_OR_NULL(key->tfm[i]))
>   			crypto_free_aead(key->tfm[i]);
>   
>   	kfree_sensitive(key);
> 

Alex, are you happy with this patch now? I would like to get it applied. 
Waiting for your review or ack given you had comments on the first version.

regards
Stefan Schmidt