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authorCatalin Marinas <catalin.marinas@arm.com>2015-02-23 18:12:56 +0000
committerDavid S. Miller <davem@davemloft.net>2015-02-23 17:22:05 -0500
commitd720d8cec563ce4e4fa44a613d4f2dcb1caf2998 (patch)
tree1e72d01e5596dc00328c161253b242a6fb7b3317 /net/compat.c
parenta948f8ce771a1f07c17ed8bcb51f59f69129a51c (diff)
downloadlinux-stericsson-d720d8cec563ce4e4fa44a613d4f2dcb1caf2998.tar.gz
net: compat: Ignore MSG_CMSG_COMPAT in compat_sys_{send, recv}msg
With commit a7526eb5d06b (net: Unbreak compat_sys_{send,recv}msg), the MSG_CMSG_COMPAT flag is blocked at the compat syscall entry points, changing the kernel compat behaviour from the one before the commit it was trying to fix (1be374a0518a, net: Block MSG_CMSG_COMPAT in send(m)msg and recv(m)msg). On 32-bit kernels (!CONFIG_COMPAT), MSG_CMSG_COMPAT is 0 and the native 32-bit sys_sendmsg() allows flag 0x80000000 to be set (it is ignored by the kernel). However, on a 64-bit kernel, the compat ABI is different with commit a7526eb5d06b. This patch changes the compat_sys_{send,recv}msg behaviour to the one prior to commit 1be374a0518a. The problem was found running 32-bit LTP (sendmsg01) binary on an arm64 kernel. Arguably, LTP should not pass 0xffffffff as flags to sendmsg() but the general rule is not to break user ABI (even when the user behaviour is not entirely sane). Fixes: a7526eb5d06b (net: Unbreak compat_sys_{send,recv}msg) Cc: Andy Lutomirski <luto@amacapital.net> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/compat.c')
-rw-r--r--net/compat.c9
1 files changed, 0 insertions, 9 deletions
diff --git a/net/compat.c b/net/compat.c
index 3236b4167a32..94d3d5e97883 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -711,24 +711,18 @@ static unsigned char nas[21] = {
COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg, unsigned int, flags)
{
- if (flags & MSG_CMSG_COMPAT)
- return -EINVAL;
return __sys_sendmsg(fd, (struct user_msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}
COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
unsigned int, vlen, unsigned int, flags)
{
- if (flags & MSG_CMSG_COMPAT)
- return -EINVAL;
return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
flags | MSG_CMSG_COMPAT);
}
COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg, unsigned int, flags)
{
- if (flags & MSG_CMSG_COMPAT)
- return -EINVAL;
return __sys_recvmsg(fd, (struct user_msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}
@@ -751,9 +745,6 @@ COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
int datagrams;
struct timespec ktspec;
- if (flags & MSG_CMSG_COMPAT)
- return -EINVAL;
-
if (timeout == NULL)
return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
flags | MSG_CMSG_COMPAT, NULL);