diff options
| author | Gustavo A. R. Silva | 2018-12-10 19:41:24 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2019-01-09 17:38:31 +0100 |
| commit | 360fb1db92dfe28145a12f48e6eefec2bf108a3a (patch) | |
| tree | 27cad73bf197e18e0b5f9b815c9150789c3542dd /net | |
| parent | ip6mr: Fix potential Spectre v1 vulnerability (diff) | |
| download | kernel-qcow2-linux-360fb1db92dfe28145a12f48e6eefec2bf108a3a.tar.gz kernel-qcow2-linux-360fb1db92dfe28145a12f48e6eefec2bf108a3a.tar.xz kernel-qcow2-linux-360fb1db92dfe28145a12f48e6eefec2bf108a3a.zip | |
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/ipmr.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 5660adcf7a04..f6275aa19b6a 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -69,6 +69,8 @@ #include <net/nexthop.h> #include <net/switchdev.h> +#include <linux/nospec.h> + struct ipmr_rule { struct fib_rule common; }; @@ -1612,6 +1614,7 @@ int ipmr_ioctl(struct sock *sk, 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)) { @@ -1686,6 +1689,7 @@ 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)) { |