[PATCH v2 1/2] ax25: Fix use of copy_from_sockptr() in ax25_setsockopt()

* [PATCH v2 1/2] ax25: Fix use of copy_from_sockptr() in ax25_setsockopt()
@ 2021-10-12 20:05 Ralf Baechle
  2021-10-12 20:05 ` [PATCH 2/2] ax25: Fix deadlock hang during concurrent read and write on socket Ralf Baechle
  0 siblings, 1 reply; 5+ messages in thread
From: Ralf Baechle @ 2021-10-12 20:05 UTC (permalink / raw)
  To: netdev
  Cc: David S. Miller, Jakub Kicinski, Christoph Hellwig,
	Thomas Osterried, linux-hams

The destination pointer passed to copy_from_sockptr() is an unsigned long *
but the source in userspace is an unsigned int.

This happens to work on 32 bit but breaks 64-bit where bytes 4..7 will not
be initialized.  By luck it may work on little endian but on big endian
where the userspace data is copied to the upper 32 bit of the destination
it's most likely going to break.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fixes: a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt")
---
 net/ax25/af_ax25.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 2631efc6e359..5e7ab76f7f9b 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -534,7 +534,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 	ax25_cb *ax25;
 	struct net_device *dev;
 	char devname[IFNAMSIZ];
-	unsigned long opt;
+	unsigned int opt;
 	int res = 0;
 
 	if (level != SOL_AX25)
@@ -566,7 +566,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T1:
-		if (opt < 1 || opt > ULONG_MAX / HZ) {
+		if (opt < 1 || opt > UINT_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
@@ -575,7 +575,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T2:
-		if (opt < 1 || opt > ULONG_MAX / HZ) {
+		if (opt < 1 || opt > UINT_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
@@ -591,7 +591,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T3:
-		if (opt < 1 || opt > ULONG_MAX / HZ) {
+		if (opt < 1 || opt > UINT_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
@@ -599,7 +599,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_IDLE:
-		if (opt > ULONG_MAX / (60 * HZ)) {
+		if (opt > UINT_MAX / (60 * HZ)) {
 			res = -EINVAL;
 			break;
 		}
-- 
2.31.1



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