Commit 4bbd360a authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

socket: Print pf->create() when it does not clear sock->sk on failure. 

I suggested to put DEBUG_NET_WARN_ON_ONCE() in __sock_create() to
catch possible use-after-free.

But the warning itself was not useful because our interest is in
the callee than the caller.

Let's define DEBUG_NET_WARN_ONCE() and print the name of pf->create()
and the socket identifier.

While at it, we enclose DEBUG_NET_WARN_ON_ONCE() in parentheses too
to avoid a checkpatch error.

Note that %pf or %pF were obsoleted and will be removed later as per
comment in lib/vsprintf.c.

Link: https://lore.kernel.org/netdev/202410231427.633734b3-lkp@intel.com/


Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241024201458.49412-1-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent f75d1fbe

include/net/net_debug.h

+3 −1
Original line number Diff line number Diff line
@@ -149,9 +149,11 @@ do { \ 




#if defined(CONFIG_DEBUG_NET)

#define DEBUG_NET_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond)

#define DEBUG_NET_WARN_ON_ONCE(cond) ((void)WARN_ON_ONCE(cond))

#define DEBUG_NET_WARN_ONCE(cond, format...) ((void)WARN_ONCE(cond, format))

#else

#define DEBUG_NET_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)

#define DEBUG_NET_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond)

#endif



#endif	/* _LINUX_NET_DEBUG_H */

net/socket.c

+3 −1
Original line number Diff line number Diff line
@@ -1578,7 +1578,9 @@ int __sock_create(struct net *net, int family, int type, int protocol, 
		/* ->create should release the allocated sock->sk object on error

		 * and make sure sock->sk is set to NULL to avoid use-after-free

		 */

		DEBUG_NET_WARN_ON_ONCE(sock->sk);

		DEBUG_NET_WARN_ONCE(sock->sk,

				    "%ps must clear sock->sk on failure, family: %d, type: %d, protocol: %d\n",

				    pf->create, family, type, protocol);

		goto out_module_put;

	}