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authorCatalin Marinas <catalin.marinas@arm.com>2015-02-23 18:12:56 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-18 13:22:27 +0100
commit83d2de946101424e79335d0d72c9288344704065 (patch)
tree7197138ddae3614ced86a3ba6aa727e648269b85 /net
parent55fde24a60ef618558fef13c2413afa5daf126df (diff)
downloadlinux-linaro-stable-83d2de946101424e79335d0d72c9288344704065.tar.gz
net: compat: Ignore MSG_CMSG_COMPAT in compat_sys_{send, recv}msg
[ Upstream commit d720d8cec563ce4e4fa44a613d4f2dcb1caf2998 ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/compat.c9
1 files changed, 0 insertions, 9 deletions
diff --git a/net/compat.c b/net/compat.c
index cbc1a2a26587..275af79c131b 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -738,24 +738,18 @@ static unsigned char nas[21] = {
asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, unsigned int flags)
{
- if (flags & MSG_CMSG_COMPAT)
- return -EINVAL;
return __sys_sendmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}
asmlinkage long compat_sys_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);
}
asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, unsigned int flags)
{
- if (flags & MSG_CMSG_COMPAT)
- return -EINVAL;
return __sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}
@@ -778,9 +772,6 @@ asmlinkage long compat_sys_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);