linux-kernel - possible double call of kfree_skb in net/llc/llc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <84ee89da0805262300v747c712ayfb60ac8aa790edb7@mail.gmail.com>
Date:	Tue, 27 May 2008 12:00:35 +0600
From:	"Dmitry Petukhov" <dmgenp@...il.com>
To:	linux-kernel@...r.kernel.org
Subject: possible double call of kfree_skb in net/llc/llc_sap.c

In the file  net/llc/llc_sap.c, funcion llc_sap_state_process,
the call to kfree_skb in the line 227 can proceed even if skb was already freed
on line 218, or  224, or queued to the user within sock_queue_rcv_skb function.
Obviously return statement is missing after line 225.

This problem was found by Alex Shevkov.

the code in question:

204 static void llc_sap_state_process(struct llc_sap *sap, struct sk_buff *skb)
205 {
206         struct llc_sap_state_ev *ev = llc_sap_ev(skb);
207
....
213         skb_get(skb);
214         ev->ind_cfm_flag = 0;
215         llc_sap_next_state(sap, skb);
216         if (ev->ind_cfm_flag == LLC_IND) {
217                 if (skb->sk->sk_state == TCP_LISTEN)
218                         kfree_skb(skb);
219                 else {
220                         llc_save_primitive(skb->sk, skb, ev->prim);
221
222                         /* queue skb to the user. */
223                         if (sock_queue_rcv_skb(skb->sk, skb))
224                                 kfree_skb(skb);
225                 }
226         }
227         kfree_skb(skb);
228 }
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/