To avoid potential format string expansion via module parameters, do not use the zpool type directly in request_module() without a format string. Additionally, to avoid arbitrary modules being loaded via zpool API (e.g. via the zswap_zpool_type module parameter) add a "zpool-" prefix to the requested module, as well as module aliases for the existing zpool types (zbud and zsmalloc). Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- v2: - moved module aliases into ifdefs (ddstreet) --- mm/zbud.c | 1 + mm/zpool.c | 2 +- mm/zsmalloc.c | 1 + 3 files changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/zbud.c b/mm/zbud.c index a05790b1915e..f26e7fcc7fa2 100644 --- a/mm/zbud.c +++ b/mm/zbud.c @@ -195,6 +195,7 @@ static struct zpool_driver zbud_zpool_driver = { .total_size = zbud_zpool_total_size, }; +MODULE_ALIAS("zpool-zbud"); #endif /* CONFIG_ZPOOL */ /***************** diff --git a/mm/zpool.c b/mm/zpool.c index e40612a1df00..739cdf0d183a 100644 --- a/mm/zpool.c +++ b/mm/zpool.c @@ -150,7 +150,7 @@ struct zpool *zpool_create_pool(char *type, gfp_t gfp, struct zpool_ops *ops) driver = zpool_get_driver(type); if (!driver) { - request_module(type); + request_module("zpool-%s", type); driver = zpool_get_driver(type); } diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 4e2fc83cb394..94f38fac5e81 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -315,6 +315,7 @@ static struct zpool_driver zs_zpool_driver = { .total_size = zs_zpool_total_size, }; +MODULE_ALIAS("zpool-zsmalloc"); #endif /* CONFIG_ZPOOL */ /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ -- 1.9.1 -- Kees Cook Chrome OS Security -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>