diff mbox series

[v2] xfrm: Zero padding when dumping algos and encap

Message ID Y+RH4Fv8yj0g535y@gondor.apana.org.au (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series [v2] xfrm: Zero padding when dumping algos and encap | expand

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Context Check Description
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 15 this patch: 15
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 15 this patch: 15
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 73 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Herbert Xu Feb. 9, 2023, 1:09 a.m. UTC 
v2 fixes the mistaken type of XFRMA_ALG_COMP for x->encap.

---8<---
When copying data to user-space we should ensure that only valid
data is copied over.  Padding in structures may be filled with
random (possibly sensitve) data and should never be given directly
to user-space.

This patch fixes the copying of xfrm algorithms and the encap
template in xfrm_user so that padding is zeroed.

Reported-by: syzbot+fa5414772d5c445dac3c@syzkaller.appspotmail.com
Reported-by: Hyunwoo Kim <v4bel@theori.io>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Comments

Sabrina Dubroca Feb. 9, 2023, 2:02 p.m. UTC | #1 
2023-02-09, 09:09:52 +0800, Herbert Xu wrote:
> v2 fixes the mistaken type of XFRMA_ALG_COMP for x->encap.
> 
> ---8<---
> When copying data to user-space we should ensure that only valid
> data is copied over.  Padding in structures may be filled with
> random (possibly sensitve) data and should never be given directly
> to user-space.
> 
> This patch fixes the copying of xfrm algorithms and the encap
> template in xfrm_user so that padding is zeroed.
> 
> Reported-by: syzbot+fa5414772d5c445dac3c@syzkaller.appspotmail.com
> Reported-by: Hyunwoo Kim <v4bel@theori.io>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Thanks Herbert.
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Steffen Klassert Feb. 14, 2023, 1:06 p.m. UTC | #2 
On Thu, Feb 09, 2023 at 03:02:11PM +0100, Sabrina Dubroca wrote:
> 2023-02-09, 09:09:52 +0800, Herbert Xu wrote:
> > v2 fixes the mistaken type of XFRMA_ALG_COMP for x->encap.
> > 
> > ---8<---
> > When copying data to user-space we should ensure that only valid
> > data is copied over.  Padding in structures may be filled with
> > random (possibly sensitve) data and should never be given directly
> > to user-space.
> > 
> > This patch fixes the copying of xfrm algorithms and the encap
> > template in xfrm_user so that padding is zeroed.
> > 
> > Reported-by: syzbot+fa5414772d5c445dac3c@syzkaller.appspotmail.com
> > Reported-by: Hyunwoo Kim <v4bel@theori.io>
> > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> 
> Thanks Herbert.
> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>

Applied, thanks a lot everyone!
diff mbox series

Patch

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index cf5172d4ce68..103af2b3e986 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1012,7 +1012,9 @@  static int copy_to_user_aead(struct xfrm_algo_aead *aead, struct sk_buff *skb)
 		return -EMSGSIZE;
 
 	ap = nla_data(nla);
-	memcpy(ap, aead, sizeof(*aead));
+	strscpy_pad(ap->alg_name, aead->alg_name, sizeof(ap->alg_name));
+	ap->alg_key_len = aead->alg_key_len;
+	ap->alg_icv_len = aead->alg_icv_len;
 
 	if (redact_secret && aead->alg_key_len)
 		memset(ap->alg_key, 0, (aead->alg_key_len + 7) / 8);
@@ -1032,7 +1034,8 @@  static int copy_to_user_ealg(struct xfrm_algo *ealg, struct sk_buff *skb)
 		return -EMSGSIZE;
 
 	ap = nla_data(nla);
-	memcpy(ap, ealg, sizeof(*ealg));
+	strscpy_pad(ap->alg_name, ealg->alg_name, sizeof(ap->alg_name));
+	ap->alg_key_len = ealg->alg_key_len;
 
 	if (redact_secret && ealg->alg_key_len)
 		memset(ap->alg_key, 0, (ealg->alg_key_len + 7) / 8);
@@ -1043,6 +1046,40 @@  static int copy_to_user_ealg(struct xfrm_algo *ealg, struct sk_buff *skb)
 	return 0;
 }
 
+static int copy_to_user_calg(struct xfrm_algo *calg, struct sk_buff *skb)
+{
+	struct nlattr *nla = nla_reserve(skb, XFRMA_ALG_COMP, sizeof(*calg));
+	struct xfrm_algo *ap;
+
+	if (!nla)
+		return -EMSGSIZE;
+
+	ap = nla_data(nla);
+	strscpy_pad(ap->alg_name, calg->alg_name, sizeof(ap->alg_name));
+	ap->alg_key_len = 0;
+
+	return 0;
+}
+
+static int copy_to_user_encap(struct xfrm_encap_tmpl *ep, struct sk_buff *skb)
+{
+	struct nlattr *nla = nla_reserve(skb, XFRMA_ENCAP, sizeof(*ep));
+	struct xfrm_encap_tmpl *uep;
+
+	if (!nla)
+		return -EMSGSIZE;
+
+	uep = nla_data(nla);
+	memset(uep, 0, sizeof(*uep));
+
+	uep->encap_type = ep->encap_type;
+	uep->encap_sport = ep->encap_sport;
+	uep->encap_dport = ep->encap_dport;
+	uep->encap_oa = ep->encap_oa;
+
+	return 0;
+}
+
 static int xfrm_smark_put(struct sk_buff *skb, struct xfrm_mark *m)
 {
 	int ret = 0;
@@ -1098,12 +1135,12 @@  static int copy_to_user_state_extra(struct xfrm_state *x,
 			goto out;
 	}
 	if (x->calg) {
-		ret = nla_put(skb, XFRMA_ALG_COMP, sizeof(*(x->calg)), x->calg);
+		ret = copy_to_user_calg(x->calg, skb);
 		if (ret)
 			goto out;
 	}
 	if (x->encap) {
-		ret = nla_put(skb, XFRMA_ENCAP, sizeof(*x->encap), x->encap);
+		ret = copy_to_user_encap(x->encap, skb);
 		if (ret)
 			goto out;
 	}