From: Alexander Lobakin Date: Thu, 4 Apr 2024 16:03:02 +0000 (+0200) Subject: ip_tunnel: harden copying IP tunnel params to userspace X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5a66cda52d7daccc88aa358872816c35093759f9;p=linux.git ip_tunnel: harden copying IP tunnel params to userspace Structures which are about to be copied to userspace shouldn't have uninitialized fields or paddings. memset() the whole &ip_tunnel_parm in ip_tunnel_parm_to_user() before filling it with the kernel data. The compilers will hopefully combine writes to it. Fixes: 117aef12a7b1 ("ip_tunnel: use a separate struct to store tunnel params in the kernel") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/netdev/5f63dd25-de94-4ca3-84e6-14095953db13@moroto.mountain Signed-off-by: Alexander Lobakin Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index f65170a28106e..177f40c3a8e8f 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -1034,6 +1034,8 @@ bool ip_tunnel_parm_to_user(void __user *data, struct ip_tunnel_parm_kern *kp) !ip_tunnel_flags_is_be16_compat(kp->o_flags)) return false; + memset(&p, 0, sizeof(p)); + strscpy(p.name, kp->name); p.link = kp->link; p.i_flags = ip_tunnel_flags_to_be16(kp->i_flags);