From 3bc93c7bded0cf361e58af160e9b23996c10a1a1 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 15 Feb 2022 09:10:17 -0800 Subject: comedi: drivers: ni_routes: Use strcmp() instead of memcmp() The family and device comparisons were using memcmp(), but this could lead to Out-of-bounds reads when the length was larger than the buffers being compared. Since these appear to always be NUL-terminated strings, just use strcmp() instead. This was found with Clang under LTO: [ 92.405851][ T1] kernel BUG at lib/string_helpers.c:980! ... [ 92.409141][ T1] RIP: 0010:fortify_panic (fbdev.c:?) ... [ 92.410056][ T1] ni_assign_device_routes (fbdev.c:?) [ 92.410056][ T1] ? unittest_enter (fbdev.c:?) [ 92.410056][ T1] ni_routes_unittest (ni_routes_test.c:?) [ 92.410056][ T1] ? unittest_enter (fbdev.c:?) [ 92.410056][ T1] __initstub__kmod_ni_routes_test__505_604_ni_routes_unittest6 (fbdev.c:?) [ 92.410056][ T1] do_one_initcall (fbdev.c:?) Link: https://lore.kernel.org/lkml/20220210072821.GD4074@xsang-OptiPlex-9020 Fixes: 4bb90c87abbe ("staging: comedi: add interface to ni routing table information") Cc: Ian Abbott Cc: H Hartley Sweeten Cc: Spencer E. Olson Cc: Greg Kroah-Hartman Cc: Masahiro Yamada Cc: Lee Jones Reported-by: kernel test robot Reviewed-by: Ian Abbott Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220215171017.1247291-1-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman --- drivers/comedi/drivers/ni_routes.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'drivers/comedi') diff --git a/drivers/comedi/drivers/ni_routes.c b/drivers/comedi/drivers/ni_routes.c index f24eeb464eba..295a3a9ee0c9 100644 --- a/drivers/comedi/drivers/ni_routes.c +++ b/drivers/comedi/drivers/ni_routes.c @@ -56,8 +56,7 @@ static const u8 *ni_find_route_values(const char *device_family) int i; for (i = 0; ni_all_route_values[i]; ++i) { - if (memcmp(ni_all_route_values[i]->family, device_family, - strnlen(device_family, 30)) == 0) { + if (!strcmp(ni_all_route_values[i]->family, device_family)) { rv = &ni_all_route_values[i]->register_values[0][0]; break; } @@ -75,8 +74,7 @@ ni_find_valid_routes(const char *board_name) int i; for (i = 0; ni_device_routes_list[i]; ++i) { - if (memcmp(ni_device_routes_list[i]->device, board_name, - strnlen(board_name, 30)) == 0) { + if (!strcmp(ni_device_routes_list[i]->device, board_name)) { dr = ni_device_routes_list[i]; break; } -- cgit v1.2.3