| From: Jeremy Cline <jcline@redhat.com> |
| Date: Fri, 27 Jul 2018 22:43:01 +0000 |
| Subject: net: socket: fix potential spectre v1 gadget in socketcall |
| |
| 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> |
| Signed-off-by: Jeremy Cline <jcline@redhat.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| 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> |
| @@ -2494,6 +2495,7 @@ 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)) |
