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| author |   Matthieu Baerts (NGI0) <matttbe@kernel.org> | 2024-02-23 21:17:55 +0100 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2024-02-26 18:42:12 -0800 |
| commit | dcc03f270d1e2f4b9715537d8deb734bd019e187 (patch) | |
| tree | 1ad91eaa6a65cdfb00abbc7b093042bd4519cb2c /net/mptcp | |
| parent | mptcp: token kunit: set protocol (diff) | |
| download | wireguard-linux-dcc03f270d1e2f4b9715537d8deb734bd019e187.tar.xz wireguard-linux-dcc03f270d1e2f4b9715537d8deb734bd019e187.zip | |
mptcp: check the protocol in tcp_sk() with DEBUG_NET
Fuzzers and static checkers might not detect when tcp_sk() is used with
a non tcp_sock structure.
This kind of mistake already happened a few times with MPTCP: when
wrongly using TCP-specific helpers with mptcp_sock pointers. On the
other hand, there are many 'tcp_xxx()' helpers that are taking a 'struct
sock' pointer as arguments, and some of them are only looking at fields
from 'struct sock', and nothing from 'struct tcp_sock'. It is then
tempting to use them with a 'struct mptcp_sock'.
So a new simple check is done when CONFIG_DEBUG_NET is enabled to tell
kernel devs when a non-TCP socket is being used as a TCP one. 'tcp_sk()'
macro is then re-defined to add a WARN when an unexpected socket is
being used.
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240223-upstream-net-next-20240223-misc-improvements-v1-3-b6c8a10396bd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/mptcp')
| -rw-r--r-- | net/mptcp/protocol.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index f89b197a9f92..026ed360bd72 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -348,6 +348,16 @@ static inline void msk_owned_by_me(const struct mptcp_sock *msk) sock_owned_by_me((const struct sock *)msk); } +#ifdef CONFIG_DEBUG_NET +/* MPTCP-specific: we might (indirectly) call this helper with the wrong sk */ +#undef tcp_sk +#define tcp_sk(ptr) ({ \ + typeof(ptr) _ptr = (ptr); \ + WARN_ON(_ptr->sk_protocol != IPPROTO_TCP); \ + container_of_const(_ptr, struct tcp_sock, inet_conn.icsk_inet.sk); \ +}) +#endif + #define mptcp_sk(ptr) container_of_const(ptr, struct mptcp_sock, sk.icsk_inet.sk) /* the msk socket don't use the backlog, also account for the bulk |