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| author |   Dmitry Safonov <dima@arista.com> | 2020-11-02 16:14:46 +0000 |
|---|---|---|
| committer |   Steffen Klassert <steffen.klassert@secunet.com> | 2020-11-09 07:34:56 +0100 |
| commit | d1949d045fd67eab8a32a579a8c1ab1681330854 (patch) | |
| tree | df7c07c22e4d531ec043d3e44d5221c638e6f77d /net/xfrm | |
| parent | xfrm/compat: Translate by copying XFRMA_UNSPEC attribute (diff) | |
| download | linux-dev-d1949d045fd67eab8a32a579a8c1ab1681330854.tar.xz linux-dev-d1949d045fd67eab8a32a579a8c1ab1681330854.zip | |
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.c | 2 |
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); |