diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-12-10 12:41:24 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-13 10:05:27 +0100 |
| commit | 74d6170eb63f458a0ddfe75f90214d7ff03c1cc2 (patch) | |
| tree | 4ed85cf40bddbe08e5a07e1438fc5f5e08cc98ff | |
| parent | 6dc50507697ce02fc8118e794b9ffdb20e6ed4ea (diff) | |
ipv4: Fix potential Spectre v1 vulnerability
[ Upstream commit 5648451e30a0d13d11796574919a359025d52cce ]
vr.vifi is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.
This issue was detected with the help of Smatch:
net/ipv4/ipmr.c:1616 ipmr_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap)
net/ipv4/ipmr.c:1690 ipmr_compat_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap)
Fix this by sanitizing vr.vifi before using it to index mrt->vif_table'
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://marc.info/?l=linux-kernel&m=152449131114778&w=2
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv4/ipmr.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 8e77786549c6..1cb865fcc91b 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -66,6 +66,7 @@ #include <net/netlink.h> #include <net/fib_rules.h> #include <linux/netconf.h> +#include <linux/nospec.h> #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2) #define CONFIG_IP_PIMSM 1 @@ -1574,6 +1575,7 @@ int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg) return -EFAULT; if (vr.vifi >= mrt->maxvif) return -EINVAL; + vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); read_lock(&mrt_lock); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) { |