Re: [PATCH] compat bug in sys_recvmsg, MSG_CMSG_COMPAT checkmissing

From: David S. Miller
Date: Sat Jun 05 2004 - 16:58:18 EST


On Sat, 05 Jun 2004 23:47:22 +0200
Andreas Schwab <schwab@xxxxxxx> wrote:

> > Olaf's patch, it said:
> >
> > - if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC))
> > + if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT))
>
> Yes, and where is the problem?

If MSG_CMSG_COMPAT is "ZERO", which it will be if CONFIG_COMPAT is
not set, then "~0" is all bits, therefore if any bit (even the ones
we want to accept) is set we will return failure. The test ends
up amounting to:

if (flags & ~0)

which is true if any bit is set, that's not what we want.

Anyways, I'm going to fix the bug like so:

# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
# 2004/06/05 14:52:04-07:00 davem@xxxxxxxxxxxxxxxxxx
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/wanrouter/af_wanpipe.c
# 2004/06/05 14:51:43-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/netrom/af_netrom.c
# 2004/06/05 14:51:43-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/econet/af_econet.c
# 2004/06/05 14:51:43-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/decnet/af_decnet.c
# 2004/06/05 14:51:43-07:00 davem@xxxxxxxxxxxxxxxxxx +2 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/x25/af_x25.c
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +2 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/rose/af_rose.c
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/packet/af_packet.c
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/key/af_key.c
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/irda/af_irda.c
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +3 -3
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/ipx/af_ipx.c
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/ax25/af_ax25.c
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -2
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# net/appletalk/ddp.c
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +1 -1
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
# include/linux/socket.h
# 2004/06/05 14:51:42-07:00 davem@xxxxxxxxxxxxxxxxxx +2 -0
# [NET]: Fix bogus msg_flags checks, need to mask out MSG_CMSG_COMPAT.
#
diff -Nru a/include/linux/socket.h b/include/linux/socket.h
--- a/include/linux/socket.h 2004-06-05 14:53:34 -07:00
+++ b/include/linux/socket.h 2004-06-05 14:53:34 -07:00
@@ -241,8 +241,10 @@

#if defined(CONFIG_COMPAT)
#define MSG_CMSG_COMPAT 0x80000000 /* This message needs 32 bit fixups */
+#define MSG_FLAGS_USER(X) ((X) & ~MSG_CMSG_COMPAT)
#else
#define MSG_CMSG_COMPAT 0 /* We never have 32 bit fixups */
+#define MSG_FLAGS_USER(X) (X)
#endif


diff -Nru a/net/appletalk/ddp.c b/net/appletalk/ddp.c
--- a/net/appletalk/ddp.c 2004-06-05 14:53:35 -07:00
+++ b/net/appletalk/ddp.c 2004-06-05 14:53:35 -07:00
@@ -1567,7 +1567,7 @@
struct atalk_route *rt;
int err;

- if (flags & ~MSG_DONTWAIT)
+ if (MSG_FLAGS_USER(flags) & ~MSG_DONTWAIT)
return -EINVAL;

if (len > DDP_MAXSZ)
diff -Nru a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
--- a/net/ax25/af_ax25.c 2004-06-05 14:53:34 -07:00
+++ b/net/ax25/af_ax25.c 2004-06-05 14:53:34 -07:00
@@ -1413,9 +1413,8 @@
size_t size;
int lv, err, addr_len = msg->msg_namelen;

- if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR)) {
+ if (MSG_FLAGS_USER(msg->msg_flags) & ~(MSG_DONTWAIT|MSG_EOR))
return -EINVAL;
- }

lock_sock(sk);
ax25 = ax25_sk(sk);
diff -Nru a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
--- a/net/decnet/af_decnet.c 2004-06-05 14:53:34 -07:00
+++ b/net/decnet/af_decnet.c 2004-06-05 14:53:34 -07:00
@@ -1905,7 +1905,8 @@
unsigned char fctype;
long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

- if (flags & ~(MSG_TRYHARD|MSG_OOB|MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|MSG_MORE))
+ if (MSG_FLAGS_USER(flags) &
+ ~(MSG_TRYHARD|MSG_OOB|MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|MSG_MORE))
return -EOPNOTSUPP;

if (addr_len && (addr_len != sizeof(struct sockaddr_dn)))
diff -Nru a/net/econet/af_econet.c b/net/econet/af_econet.c
--- a/net/econet/af_econet.c 2004-06-05 14:53:34 -07:00
+++ b/net/econet/af_econet.c 2004-06-05 14:53:34 -07:00
@@ -274,7 +274,7 @@
* Check the flags.
*/

- if (msg->msg_flags&~MSG_DONTWAIT)
+ if (MSG_FLAGS_USER(msg->msg_flags) & ~MSG_DONTWAIT)
return(-EINVAL);

/*
diff -Nru a/net/ipx/af_ipx.c b/net/ipx/af_ipx.c
--- a/net/ipx/af_ipx.c 2004-06-05 14:53:34 -07:00
+++ b/net/ipx/af_ipx.c 2004-06-05 14:53:34 -07:00
@@ -1695,7 +1695,7 @@
/* Socket gets bound below anyway */
/* if (sk->sk_zapped)
return -EIO; */ /* Socket not bound */
- if (flags & ~MSG_DONTWAIT)
+ if (MSG_FLAGS_USER(flags) & ~MSG_DONTWAIT)
goto out;

/* Max possible packet size limited by 16 bit pktsize in header */
diff -Nru a/net/irda/af_irda.c b/net/irda/af_irda.c
--- a/net/irda/af_irda.c 2004-06-05 14:53:34 -07:00
+++ b/net/irda/af_irda.c 2004-06-05 14:53:34 -07:00
@@ -1269,7 +1269,7 @@
IRDA_DEBUG(4, "%s(), len=%d\n", __FUNCTION__, len);

/* Note : socket.c set MSG_EOR on SEQPACKET sockets */
- if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_EOR))
+ if (MSG_FLAGS_USER(msg->msg_flags) & ~(MSG_DONTWAIT | MSG_EOR))
return -EINVAL;

if (sk->sk_shutdown & SEND_SHUTDOWN) {
@@ -1521,7 +1521,7 @@

IRDA_DEBUG(4, "%s(), len=%d\n", __FUNCTION__, len);

- if (msg->msg_flags & ~MSG_DONTWAIT)
+ if (MSG_FLAGS_USER(msg->msg_flags) & ~MSG_DONTWAIT)
return -EINVAL;

if (sk->sk_shutdown & SEND_SHUTDOWN) {
@@ -1593,7 +1593,7 @@

IRDA_DEBUG(4, "%s(), len=%d\n", __FUNCTION__, len);

- if (msg->msg_flags & ~MSG_DONTWAIT)
+ if (MSG_FLAGS_USER(msg->msg_flags) & ~MSG_DONTWAIT)
return -EINVAL;

if (sk->sk_shutdown & SEND_SHUTDOWN) {
diff -Nru a/net/key/af_key.c b/net/key/af_key.c
--- a/net/key/af_key.c 2004-06-05 14:53:34 -07:00
+++ b/net/key/af_key.c 2004-06-05 14:53:34 -07:00
@@ -2726,7 +2726,7 @@
int copied, err;

err = -EINVAL;
- if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC))
+ if (MSG_FLAGS_USER(flags) & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC))
goto out;

msg->msg_namelen = 0;
diff -Nru a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
--- a/net/netrom/af_netrom.c 2004-06-05 14:53:34 -07:00
+++ b/net/netrom/af_netrom.c 2004-06-05 14:53:34 -07:00
@@ -1021,7 +1021,7 @@
unsigned char *asmptr;
int size;

- if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR))
+ if (MSG_FLAGS_USER(msg->msg_flags) & ~(MSG_DONTWAIT|MSG_EOR))
return -EINVAL;

lock_sock(sk);
diff -Nru a/net/packet/af_packet.c b/net/packet/af_packet.c
--- a/net/packet/af_packet.c 2004-06-05 14:53:34 -07:00
+++ b/net/packet/af_packet.c 2004-06-05 14:53:34 -07:00
@@ -1037,7 +1037,7 @@
int copied, err;

err = -EINVAL;
- if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC))
+ if (MSG_FLAGS_USER(flags) & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC))
goto out;

#if 0
diff -Nru a/net/rose/af_rose.c b/net/rose/af_rose.c
--- a/net/rose/af_rose.c 2004-06-05 14:53:34 -07:00
+++ b/net/rose/af_rose.c 2004-06-05 14:53:34 -07:00
@@ -1021,7 +1021,7 @@
unsigned char *asmptr;
int n, size, qbit = 0;

- if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR))
+ if (MSG_FLAGS_USER(msg->msg_flags) & ~(MSG_DONTWAIT|MSG_EOR))
return -EINVAL;

if (sk->sk_zapped)
diff -Nru a/net/wanrouter/af_wanpipe.c b/net/wanrouter/af_wanpipe.c
--- a/net/wanrouter/af_wanpipe.c 2004-06-05 14:53:34 -07:00
+++ b/net/wanrouter/af_wanpipe.c 2004-06-05 14:53:35 -07:00
@@ -552,7 +552,7 @@
if (sk->sk_state != WANSOCK_CONNECTED)
return -ENOTCONN;

- if (msg->msg_flags&~MSG_DONTWAIT)
+ if (MSG_FLAGS_USER(msg->msg_flags) & ~MSG_DONTWAIT)
return(-EINVAL);

/* it was <=, now one can send
diff -Nru a/net/x25/af_x25.c b/net/x25/af_x25.c
--- a/net/x25/af_x25.c 2004-06-05 14:53:34 -07:00
+++ b/net/x25/af_x25.c 2004-06-05 14:53:34 -07:00
@@ -922,7 +922,8 @@
size_t size;
int qbit = 0, rc = -EINVAL;

- if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_OOB | MSG_EOR))
+ if (MSG_FLAGS_USER(msg->msg_flags) &
+ ~(MSG_DONTWAIT | MSG_OOB | MSG_EOR))
goto out;

/* we currently don't support segmented records at the user interface */
-
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