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authorGustavo A. R. Silva <gustavo@embeddedor.com>2019-01-09 17:39:06 -0600
committerCorey Minyard <cminyard@mvista.com>2019-01-23 10:44:23 -0600
commita7102c7461794a5bb31af24b08e9e0f50038897a (patch)
treea3037c4ff4591c602b4746e948056da0940b5ad9 /drivers
parent7d6380cd40f7993f75c4bde5b36f6019237e8719 (diff)
downloadlinux-a7102c7461794a5bb31af24b08e9e0f50038897a.tar.bz2
ipmi: msghandler: Fix potential Spectre v1 vulnerabilities
channel and addr->channel are indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. These issues were detected with the help of Smatch: drivers/char/ipmi/ipmi_msghandler.c:1381 ipmi_set_my_address() warn: potential spectre issue 'user->intf->addrinfo' [w] (local cap) drivers/char/ipmi/ipmi_msghandler.c:1401 ipmi_get_my_address() warn: potential spectre issue 'user->intf->addrinfo' [r] (local cap) drivers/char/ipmi/ipmi_msghandler.c:1421 ipmi_set_my_LUN() warn: potential spectre issue 'user->intf->addrinfo' [w] (local cap) drivers/char/ipmi/ipmi_msghandler.c:1441 ipmi_get_my_LUN() warn: potential spectre issue 'user->intf->addrinfo' [r] (local cap) drivers/char/ipmi/ipmi_msghandler.c:2260 check_addr() warn: potential spectre issue 'intf->addrinfo' [r] (local cap) Fix this by sanitizing channel and addr->channel before using them to index user->intf->addrinfo and intf->addrinfo, correspondingly. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/ Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/char/ipmi/ipmi_msghandler.c26
1 files changed, 18 insertions, 8 deletions
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index a74ce885b541..7a9fbe60a840 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -32,6 +32,7 @@
#include <linux/moduleparam.h>
#include <linux/workqueue.h>
#include <linux/uuid.h>
+#include <linux/nospec.h>
#define IPMI_DRIVER_VERSION "39.2"
@@ -1298,10 +1299,12 @@ int ipmi_set_my_address(struct ipmi_user *user,
if (!user)
return -ENODEV;
- if (channel >= IPMI_MAX_CHANNELS)
+ if (channel >= IPMI_MAX_CHANNELS) {
rv = -EINVAL;
- else
+ } else {
+ channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
user->intf->addrinfo[channel].address = address;
+ }
release_ipmi_user(user, index);
return rv;
@@ -1318,10 +1321,12 @@ int ipmi_get_my_address(struct ipmi_user *user,
if (!user)
return -ENODEV;
- if (channel >= IPMI_MAX_CHANNELS)
+ if (channel >= IPMI_MAX_CHANNELS) {
rv = -EINVAL;
- else
+ } else {
+ channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
*address = user->intf->addrinfo[channel].address;
+ }
release_ipmi_user(user, index);
return rv;
@@ -1338,10 +1343,12 @@ int ipmi_set_my_LUN(struct ipmi_user *user,
if (!user)
return -ENODEV;
- if (channel >= IPMI_MAX_CHANNELS)
+ if (channel >= IPMI_MAX_CHANNELS) {
rv = -EINVAL;
- else
+ } else {
+ channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
user->intf->addrinfo[channel].lun = LUN & 0x3;
+ }
release_ipmi_user(user, index);
return rv;
@@ -1358,10 +1365,12 @@ int ipmi_get_my_LUN(struct ipmi_user *user,
if (!user)
return -ENODEV;
- if (channel >= IPMI_MAX_CHANNELS)
+ if (channel >= IPMI_MAX_CHANNELS) {
rv = -EINVAL;
- else
+ } else {
+ channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
*address = user->intf->addrinfo[channel].lun;
+ }
release_ipmi_user(user, index);
return rv;
@@ -2184,6 +2193,7 @@ static int check_addr(struct ipmi_smi *intf,
{
if (addr->channel >= IPMI_MAX_CHANNELS)
return -EINVAL;
+ addr->channel = array_index_nospec(addr->channel, IPMI_MAX_CHANNELS);
*lun = intf->addrinfo[addr->channel].lun;
*saddr = intf->addrinfo[addr->channel].address;
return 0;