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| author | Eric Dumazet <edumazet@google.com> | 2017-02-13 01:03:52 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-18 08:55:48 +0300 |
| commit | 5b8f1011ac5363df3a6051223d146144f4af47d7 (patch) | |
| tree | befbe9f71de256e3c74fa7f1bbbb289ba7e29553 /net/llc | |
| parent | 18c424603ef590045486c43d9f74f32551a069d8 (diff) | |
| download | linux-5b8f1011ac5363df3a6051223d146144f4af47d7.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>
Diffstat (limited to 'net/llc')
| -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 42dc2e45c921..9c68d0bca046 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 06033f6c845f..cdc1b620cbe1 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); } |