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| author | Eric Dumazet <edumazet@google.com> | 2017-02-13 01:03:52 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-26 13:10:50 +0300 |
| commit | 42b52783a59cc706c71cdc7096edce4a6f086fd3 (patch) | |
| tree | 7a5debd3bf6fcaf24a0c253449f5c3b039a2bf61 | |
| parent | 859900c24bff90768e1789bd93e1b51fa726a659 (diff) | |
| download | linux-42b52783a59cc706c71cdc7096edce4a6f086fd3.tar.xz | |
net/llc: avoid BUG_ON() in skb_orphan()
[ Upstream commit 8b74d439e1697110c5e5c600643e823eb1dd0762 ]
It seems nobody used LLC since linux-3.12.
Fortunately fuzzers like syzkaller still know how to run this code,
otherwise it would be no fun.
Setting skb->sk without skb->destructor leads to all kinds of
bugs, we now prefer to be very strict about it.
Ideally here we would use skb_set_owner() but this helper does not exist yet,
only CAN seems to have a private helper for that.
Fixes: 376c7311bdb6 ("net: add a temporary sanity check in skb_orphan()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/llc/llc_conn.c | 3 | ||||
| -rw-r--r-- | net/llc/llc_sap.c | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c index 3e821daf9dd4..8bc5a1bd2d45 100644 --- a/net/llc/llc_conn.c +++ b/net/llc/llc_conn.c @@ -821,7 +821,10 @@ void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb) * another trick required to cope with how the PROCOM state * machine works. -acme */ + skb_orphan(skb); + sock_hold(sk); skb->sk = sk; + skb->destructor = sock_efree; } if (!sock_owned_by_user(sk)) llc_conn_rcv(sk, skb); diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c index d0e1e804ebd7..5404d0d195cc 100644 --- a/net/llc/llc_sap.c +++ b/net/llc/llc_sap.c @@ -290,7 +290,10 @@ static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb, ev->type = LLC_SAP_EV_TYPE_PDU; ev->reason = 0; + skb_orphan(skb); + sock_hold(sk); skb->sk = sk; + skb->destructor = sock_efree; llc_sap_state_process(sap, skb); } |