2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Mathias Krause <[email protected]> commit 43da5f2e0d0c69ded3d51907d9552310a6b545e8 upstream. 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 <[email protected]> Signed-off-by: David S. Miller <[email protected]> [bwh: Backported to 2.6.32: adjust filename, context] Signed-off-by: Willy Tarreau <[email protected]> --- fs/compat_ioctl.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index 0dd21a4..98d3c58 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -352,6 +352,7 @@ static int dev_ifconf(unsigned int fd, unsigned int cmd, unsigned long arg) if (copy_from_user(&ifc32, compat_ptr(arg), sizeof(struct ifconf32))) return -EFAULT; + memset(&ifc, 0, sizeof(ifc)); if (ifc32.ifcbuf == 0) { ifc32.ifc_len = 0; ifc.ifc_len = 0; -- 1.7.12.2.21.g234cd45.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
