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| author |   Gustavo A. R. Silva <gustavo@embeddedor.com> | 2019-01-09 17:39:06 -0600 |
|---|---|---|
| committer |   Corey Minyard <cminyard@mvista.com> | 2019-01-23 10:44:23 -0600 |
| commit | a7102c7461794a5bb31af24b08e9e0f50038897a (patch) | |
| tree | a3037c4ff4591c602b4746e948056da0940b5ad9 /drivers/char | |
| parent | ipmi:ssif: Fix handling of multi-part return messages (diff) | |
| download | linux-dev-a7102c7461794a5bb31af24b08e9e0f50038897a.tar.xz linux-dev-a7102c7461794a5bb31af24b08e9e0f50038897a.zip | |
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/char')
| -rw-r--r-- | drivers/char/ipmi/ipmi_msghandler.c | 26 |
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; |