4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jeremy Cline jcline@redhat.com
commit c8e8cd579bb4265651df8223730105341e61a2d1 upstream.
'call' is a user-controlled value, so sanitize the array index after the bounds check to avoid speculating past the bounds of the 'nargs' array.
Found with the help of Smatch:
net/socket.c:2508 __do_sys_socketcall() warn: potential spectre issue 'nargs' [r] (local cap)
Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Jeremy Cline jcline@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/socket.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/net/socket.c +++ b/net/socket.c @@ -89,6 +89,7 @@ #include <linux/magic.h> #include <linux/slab.h> #include <linux/xattr.h> +#include <linux/nospec.h>
#include <asm/uaccess.h> #include <asm/unistd.h> @@ -2324,6 +2325,7 @@ SYSCALL_DEFINE2(socketcall, int, call, u
if (call < 1 || call > SYS_SENDMMSG) return -EINVAL; + call = array_index_nospec(call, SYS_SENDMMSG + 1);
len = nargs[call]; if (len > sizeof(a))