Commit 9261c9b0 authored Sep 06, 2005 by Eric Dumazet Committed by David S. Miller Sep 06, 2005

[NET]: Make sure l_linger is unsigned to avoid negative timeouts



One of my x86_64 (linux 2.6.13) server log is filled with :

schedule_timeout: wrong timeout value ffffffffffffff06 from ffffffff802e63ca
schedule_timeout: wrong timeout value ffffffffffffff06 from ffffffff802e63ca
schedule_timeout: wrong timeout value ffffffffffffff06 from ffffffff802e63ca
schedule_timeout: wrong timeout value ffffffffffffff06 from ffffffff802e63ca
schedule_timeout: wrong timeout value ffffffffffffff06 from ffffffff802e63ca

This is because some application does a

struct linger li;
li.l_onoff = 1;
li.l_linger = -1;
setsockopt(sock, SOL_SOCKET, SO_LINGER, &li, sizeof(li));

And unfortunatly l_linger is defined as a 'signed int' in
include/linux/socket.h:

struct linger {
         int             l_onoff;        /* Linger active                */
         int             l_linger;       /* How long to linger for       */
};

I dont know if it's safe to change l_linger to 'unsigned int' in the
include file (It might be defined as int in ABI specs)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent fe2d5295

net/core/sock.c

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -341,11 +341,11 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
	sock_reset_flag(sk, SOCK_LINGER);		sock_reset_flag(sk, SOCK_LINGER);
	else {		else {
	#if (BITS_PER_LONG == 32)		#if (BITS_PER_LONG == 32)
	if (ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)		if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
	sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;		sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
	else		else
	#endif		#endif
	sk->sk_lingertime = ling.l_linger * HZ;		sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
	sock_set_flag(sk, SOCK_LINGER);		sock_set_flag(sk, SOCK_LINGER);
	}		}
	break;		break;