From 43da5f2e0d0c69ded3d51907d9552310a6b545e8 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Wed, 15 Aug 2012 11:31:57 +0000 Subject: net: fix info leak in compat dev_ifconf() The implementation of dev_ifconf() for the compat ioctl interface uses an intermediate ifc structure allocated in userland for the duration of the syscall. Though, it fails to initialize the padding bytes inserted for alignment and that for leaks four bytes of kernel stack. Add an explicit memset(0) before filling the structure to avoid the info leak. Signed-off-by: Mathias Krause Signed-off-by: David S. Miller --- net/socket.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/socket.c') diff --git a/net/socket.c b/net/socket.c index dfe5b66c97e..a5471f804d9 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2657,6 +2657,7 @@ static int dev_ifconf(struct net *net, struct compat_ifconf __user *uifc32) if (copy_from_user(&ifc32, uifc32, sizeof(struct compat_ifconf))) return -EFAULT; + memset(&ifc, 0, sizeof(ifc)); if (ifc32.ifcbuf == 0) { ifc32.ifc_len = 0; ifc.ifc_len = 0; -- cgit v1.2.3-70-g09d2 From ed6fe9d614fc1bca95eb8c0ccd0e92db00ef9d5d Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Sat, 1 Sep 2012 12:34:07 -0400 Subject: Fix order of arguments to compat_put_time[spec|val] Commit 644595f89620 ("compat: Handle COMPAT_USE_64BIT_TIME in net/socket.c") introduced a bug where the helper functions to take either a 64-bit or compat time[spec|val] got the arguments in the wrong order, passing the kernel stack pointer off as a user pointer (and vice versa). Because of the user address range check, that in turn then causes an EFAULT due to the user pointer range checking failing for the kernel address. Incorrectly resuling in a failed system call for 32-bit processes with a 64-bit kernel. On odder architectures like HP-PA (with separate user/kernel address spaces), it can be used read kernel memory. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds --- net/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/socket.c') diff --git a/net/socket.c b/net/socket.c index a5471f804d9..edc3c4af908 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2604,7 +2604,7 @@ static int do_siocgstamp(struct net *net, struct socket *sock, err = sock_do_ioctl(net, sock, cmd, (unsigned long)&ktv); set_fs(old_fs); if (!err) - err = compat_put_timeval(up, &ktv); + err = compat_put_timeval(&ktv, up); return err; } @@ -2620,7 +2620,7 @@ static int do_siocgstampns(struct net *net, struct socket *sock, err = sock_do_ioctl(net, sock, cmd, (unsigned long)&kts); set_fs(old_fs); if (!err) - err = compat_put_timespec(up, &kts); + err = compat_put_timespec(&kts, up); return err; } -- cgit v1.2.3-70-g09d2