diff options
| author | Herbert Xu | 2023-02-09 09:09:52 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-04-06 12:10:37 +0200 |
| commit | 5218af4ad5d8948faac19f71583bcd786c3852df (patch) | |
| tree | 810d0f59f0bf0f89f8a06338b83f4c1934ee567d | |
| parent | 2b4830eefc41b06d4943ae860abf24ec3901d89f (diff) | |
xfrm: Zero padding when dumping algos and encap
[ Upstream commit 8222d5910dae08213b6d9d4bc9a7f8502855e624 ]
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>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/xfrm/xfrm_user.c | 45 |
1 files changed, 41 insertions, 4 deletions
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index e73f9efc54c1..83f35ecacf24 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -997,7 +997,9 @@ 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); @@ -1017,7 +1019,8 @@ 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); @@ -1028,6 +1031,40 @@ 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; @@ -1083,12 +1120,12 @@ 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; } |