From df32de1433412621b92daf1b3369ac053214031e Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Tue, 3 Jan 2023 12:01:19 +0900 Subject: [PATCH] zram: correctly handle all next_arg() cases When supplied buffer does not have assignment sign next_arg() sets `val` pointer to NULL, so we cannot dereference it. Add a NULL pointer test to handle `param` case, in addition to `*val` test, which handles cases when param has no value assigned to it: `param=`. Link: https://lkml.kernel.org/r/20230103030119.1496358-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Cc: Minchan Kim Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 7becd54..5d1088a 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1140,7 +1140,7 @@ static ssize_t recomp_algorithm_store(struct device *dev, while (*args) { args = next_arg(args, ¶m, &val); - if (!*val) + if (!val || !*val) return -EINVAL; if (!strcmp(param, "algo")) { @@ -1824,7 +1824,7 @@ static ssize_t recompress_store(struct device *dev, while (*args) { args = next_arg(args, ¶m, &val); - if (!*val) + if (!val || !*val) return -EINVAL; if (!strcmp(param, "type")) { -- 2.7.4