From 0f1aab4b37ce87d5093bad9c6d196b0ebcc09f72 Mon Sep 17 00:00:00 2001 From: Dmitry Safonov Date: Mon, 21 Sep 2020 15:36:56 +0100 Subject: [PATCH] BACKPORT: xfrm/compat: Translate 32-bit user_policy from sockptr Provide compat_xfrm_userpolicy_info translation for xfrm setsocketopt(). Reallocate buffer and put the missing padding for 64-bit message. Signed-off-by: Dmitry Safonov Signed-off-by: Steffen Klassert (cherry picked from commit 96392ee5a13b992563cfe07d23ee30d333b89126) [adelva: Edited around removed compat check in Android kernels] Bug: 163141236 Signed-off-by: Alistair Delva Change-Id: I32a6495cd92fa13c956fca88aa5d80716155b8ae --- include/net/xfrm.h | 3 +++ net/xfrm/xfrm_compat.c | 26 ++++++++++++++++++++++++++ net/xfrm/xfrm_state.c | 14 ++++++++++++++ 3 files changed, 43 insertions(+) diff --git a/include/net/xfrm.h b/include/net/xfrm.h index fd4361a911e7..1078828580d2 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -2106,6 +2106,9 @@ struct xfrm_translator { int maxtype, const struct nla_policy *policy, struct netlink_ext_ack *extack); + /* Translate 32-bit user_policy from sockptr */ + int (*xlate_user_policy_sockptr)(u8 **pdata32, int optlen); + struct module *owner; }; diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c index d3b83327b10f..6f597ba266ca 100644 --- a/net/xfrm/xfrm_compat.c +++ b/net/xfrm/xfrm_compat.c @@ -576,10 +576,36 @@ static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32, return h64; } +static int xfrm_user_policy_compat(u8 **pdata32, int optlen) +{ + struct compat_xfrm_userpolicy_info *p = (void *)*pdata32; + u8 *src_templates, *dst_templates; + u8 *data64; + + if (optlen < sizeof(*p)) + return -EINVAL; + + data64 = kmalloc(optlen + 4, GFP_USER | __GFP_NOWARN); + if (!data64) + return -ENOMEM; + + memcpy(data64, *pdata32, sizeof(*p)); + memset(data64 + sizeof(*p), 0, 4); + + src_templates = *pdata32 + sizeof(*p); + dst_templates = data64 + sizeof(*p) + 4; + memcpy(dst_templates, src_templates, optlen - sizeof(*p)); + + kfree(*pdata32); + *pdata32 = data64; + return 0; +} + static struct xfrm_translator xfrm_translator = { .owner = THIS_MODULE, .alloc_compat = xfrm_alloc_compat, .rcv_msg_compat = xfrm_user_rcv_msg_compat, + .xlate_user_policy_sockptr = xfrm_user_policy_compat, }; static int __init xfrm_compat_init(void) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 9d69f10e6043..263f7adf7865 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -2199,6 +2199,20 @@ int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen if (IS_ERR(data)) return PTR_ERR(data); + if (in_compat_syscall()) { + struct xfrm_translator *xtr = xfrm_get_translator(); + + if (!xtr) + return -EOPNOTSUPP; + + err = xtr->xlate_user_policy_sockptr(&data, optlen); + xfrm_put_translator(xtr); + if (err) { + kfree(data); + return err; + } + } + err = -EINVAL; rcu_read_lock(); list_for_each_entry_rcu(km, &xfrm_km_list, list) {