From 8920e8f94c44e31a73bdf923b04721e26e88cadd Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 7 Sep 2005 18:28:51 -0700 Subject: [PATCH] Fix 32bit sendmsg() flaw When we copy 32bit ->msg_control contents to kernel, we walk the same userland data twice without sanity checks on the second pass. Second version of this patch: the original broke with 64-bit arches running 32-bit-compat-mode executables doing sendmsg() syscalls with unaligned CMSG data areas Another thing is that we use kmalloc() to allocate and sock_kfree_s() to free afterwards; less serious, but also needs fixing. Signed-off-by: Al Viro Signed-off-by: David Woodhouse Signed-off-by: Chris Wright Signed-off-by: Linus Torvalds --- net/socket.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/socket.c') diff --git a/net/socket.c b/net/socket.c index e1bd5d84d7bf..c699e93c33d7 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1745,10 +1745,11 @@ asmlinkage long sys_sendmsg(int fd, struct msghdr __user *msg, unsigned flags) goto out_freeiov; ctl_len = msg_sys.msg_controllen; if ((MSG_CMSG_COMPAT & flags) && ctl_len) { - err = cmsghdr_from_user_compat_to_kern(&msg_sys, ctl, sizeof(ctl)); + err = cmsghdr_from_user_compat_to_kern(&msg_sys, sock->sk, ctl, sizeof(ctl)); if (err) goto out_freeiov; ctl_buf = msg_sys.msg_control; + ctl_len = msg_sys.msg_controllen; } else if (ctl_len) { if (ctl_len > sizeof(ctl)) { -- cgit v1.2.3-59-g8ed1b