commit 547ce4cfb34c ("switch cmsghdr_from_user_compat_to_kern() to
copy_from_user()") missed one of the places where ucmlen should've been
replaced with cmsg.cmsg_len, now that we are fetching the entire struct
rather than doing it field-by-field.
As the result, compat sendmsg() with several different-sized cmsg
attached started to fail with EINVAL. Trivial to fix, fortunately.
Reported-by: Nick Bowler <nbow...@draconx.ca>
Tested-by: Nick Bowler <nbow...@draconx.ca>
Fixes: 547ce4cfb34c ("switch cmsghdr_from_user_compat_to_kern() to
copy_from_user()")
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
diff --git a/net/compat.c b/net/compat.c
index 5e3041a2c37d..434838bef5f8 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -202,7 +202,7 @@ int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg,
struct sock *sk,
/* Advance. */
kcmsg = (struct cmsghdr *)((char *)kcmsg + tmp);
- ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
+ ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, cmsg.cmsg_len);
}
/*
