'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@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jeremy Cline <jcline@xxxxxxxxxx> --- net/socket.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/socket.c b/net/socket.c index 3015ddace71e..f15d5cbb3ba4 100644 --- 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 <linux/uaccess.h> #include <asm/unistd.h> @@ -2504,6 +2505,7 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args) if (call < 1 || call > SYS_SENDMMSG) return -EINVAL; + call = array_index_nospec(call, SYS_SENDMMSG + 1); len = nargs[call]; if (len > sizeof(a)) -- 2.17.1
