From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Subject: lib/cmdline: fix get_option() for strings starting with hyphen When string doesn't have an integer and starts from hyphen get_option() may return interesting results. Fix it to return 0. The simple_strtoull() is used due to absence of simple_strtoul() in a boot code on some architectures. Note, the Fixes tag below is rather for anthropological curiosity. Link: https://lkml.kernel.org/r/20201112180732.75589-4-andriy.shevchenko@xxxxxxxxxxxxxxx Fixes: f68565831e72 ("Import 2.4.0-test2pre3") Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: Brendan Higgins <brendanhiggins@xxxxxxxxxx> Cc: David Gow <davidgow@xxxxxxxxxx> Cc: Mark Brown <broonie@xxxxxxxxxx> Cc: Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx> Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Cc: Vitor Massaru Iha <vitor@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/cmdline.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/lib/cmdline.c~lib-cmdline-fix-get_option-for-strings-starting-with-hyphen +++ a/lib/cmdline.c @@ -45,6 +45,9 @@ static int get_range(char **str, int *pi * 1 - int found, no subsequent comma * 2 - int found including a subsequent comma * 3 - hyphen found to denote a range + * + * Leading hyphen without integer is no integer case, but we consume it + * for the sake of simplification. */ int get_option(char **str, int *pint) @@ -53,7 +56,10 @@ int get_option(char **str, int *pint) if (!cur || !(*cur)) return 0; - *pint = simple_strtol(cur, str, 0); + if (*cur == '-') + *pint = -simple_strtoull(++cur, str, 0); + else + *pint = simple_strtoull(cur, str, 0); if (cur == *str) return 0; if (**str == ',') { _
