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| author | Tom Parkin <tparkin@katalix.com> | 2020-07-24 16:31:53 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-07-24 17:19:14 -0700 |
| commit | 1aa646ac71feb987a9571e1d70980d10ff495fbc (patch) | |
| tree | adc957c6c656ed86abc5f4dd7655d492db5e9d37 /net/l2tp | |
| parent | cd3e29b333cc2571a5875d1b45c460dc948a2f95 (diff) | |
| download | lwn-1aa646ac71feb987a9571e1d70980d10ff495fbc.tar.gz lwn-1aa646ac71feb987a9571e1d70980d10ff495fbc.zip | |
l2tp: don't BUG_ON session magic checks in l2tp_ppp
checkpatch advises that WARN_ON and recovery code are preferred over
BUG_ON which crashes the kernel.
l2tp_ppp.c's BUG_ON checks of the l2tp session structure's "magic" field
occur in code paths where it's reasonably easy to recover:
* In the case of pppol2tp_sock_to_session, we can return NULL and the
caller will bail out appropriately. There is no change required to
any of the callsites of this function since they already handle
pppol2tp_sock_to_session returning NULL.
* In the case of pppol2tp_session_destruct we can just avoid
decrementing the reference count on the suspect session structure.
In the worst case scenario this results in a memory leak, which is
preferable to a crash.
Convert these uses of BUG_ON to WARN_ON accordingly.
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/l2tp')
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index 4389df66af35..2aeee648c080 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -163,8 +163,11 @@ static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) sock_put(sk); goto out; } - - BUG_ON(session->magic != L2TP_SESSION_MAGIC); + if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) { + session = NULL; + sock_put(sk); + goto out; + } out: return session; @@ -419,7 +422,8 @@ static void pppol2tp_session_destruct(struct sock *sk) if (session) { sk->sk_user_data = NULL; - BUG_ON(session->magic != L2TP_SESSION_MAGIC); + if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) + return; l2tp_session_dec_refcount(session); } } |