2019-07-29 12:14:30

by Jia-Ju Bai

Subject: [PATCH] scsi: libiscsi: Fix possible null-pointer dereferences in iscsi_conn_get_addr_param()

In iscsi_conn_get_addr_param(), sin6 may be NULL when reaching lines
3479 and 3487:
len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
len = sprintf(buf, "%hu\n", be16_to_cpu(sin6->sin6_port));

Thus, possible null-pointer dereferences may occur.

To fix these bugs, sin6 is checked before being used, and len is
initialized to -EINVAL.

These bugs are found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
drivers/scsi/libiscsi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index ebd47c0cf9e9..58f072d5c43f 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -3457,7 +3457,7 @@ int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
{
struct sockaddr_in6 *sin6 = NULL;
struct sockaddr_in *sin = NULL;
- int len;
+ int len = -EINVAL;

switch (addr->ss_family) {
case AF_INET:
@@ -3475,14 +3475,14 @@ int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
case ISCSI_HOST_PARAM_IPADDRESS:
if (sin)
len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
- else
+ else if (sin6)
len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
break;
case ISCSI_PARAM_CONN_PORT:
case ISCSI_PARAM_LOCAL_PORT:
if (sin)
len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
- else
+ else if (sin6)
len = sprintf(buf, "%hu\n",
be16_to_cpu(sin6->sin6_port));
break;
--
2.17.0

2019-08-27 05:36:05

by Markus Elfring

Subject: Re: libiscsi: Fix possible null-pointer dereferences in iscsi_conn_get_addr_param()

> These bugs are found by a static analysis tool STCheck written by us.

Would you like to improve any more commit descriptions also by
adjusting such a wording?

Regards,
Markus