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authorDmitry Safonov <dima@arista.com>2020-11-02 16:14:46 +0000
committerSteffen Klassert <steffen.klassert@secunet.com>2020-11-09 07:34:56 +0100
commitd1949d045fd67eab8a32a579a8c1ab1681330854 (patch)
treedf7c07c22e4d531ec043d3e44d5221c638e6f77d /net/xfrm
parentdbd7ae5154d5fff7e84a9f3010bb06499017ef29 (diff)
xfrm/compat: memset(0) 64-bit padding at right place
32-bit messages translated by xfrm_compat can have attributes attached. For all, but XFRMA_SA, XFRMA_POLICY the size of payload is the same in 32-bit UABI and 64-bit UABI. For XFRMA_SA (struct xfrm_usersa_info) and XFRMA_POLICY (struct xfrm_userpolicy_info) it's only tail-padding that is present in 64-bit payload, but not in 32-bit. The proper size for destination nlattr is already calculated by xfrm_user_rcv_calculate_len64() and allocated with kvmalloc(). xfrm_attr_cpy32() copies 32-bit copy_len into 64-bit attribute translated payload, zero-filling possible padding for SA/POLICY. Due to a typo, *pos already has 64-bit payload size, in a result next memset(0) is called on the memory after the translated attribute, not on the tail-padding of it. Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator") Reported-by: syzbot+c43831072e7df506a646@syzkaller.appspotmail.com Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm')
-rw-r--r--net/xfrm/xfrm_compat.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c
index 17edbf935e35..556e9f33b815 100644
--- a/net/xfrm/xfrm_compat.c
+++ b/net/xfrm/xfrm_compat.c
@@ -388,7 +388,7 @@ static int xfrm_attr_cpy32(void *dst, size_t *pos, const struct nlattr *src,
memcpy(nla, src, nla_attr_size(copy_len));
nla->nla_len = nla_attr_size(payload);
- *pos += nla_attr_size(payload);
+ *pos += nla_attr_size(copy_len);
nlmsg->nlmsg_len += nla->nla_len;
memset(dst + *pos, 0, payload - copy_len);