On Thu, Apr 10, 2025 at 07:45:29PM +0800, Zijun Hu wrote:
> From: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
>
> Constant table array array[] which must end with a empty entry and fix
> below issues for validate_constant_table(array, ARRAY_SIZE(array), ...):
>
> - Always return wrong value for good constant table array which ends
> with a empty entry.
>
> - Imprecise error message for missorted case.
>
> - Potential NULL pointer dereference.
I really dislike "potential NULL deref" without an explanation. Please
explain how this supposed NULL deref can happen.
> Fixes: 31d921c7fb96 ("vfs: Add configuration parser helpers")
> Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
> ---
> fs/fs_parser.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/fs/fs_parser.c b/fs/fs_parser.c
> index e635a81e17d965df78ffef27f6885cd70996c6dd..ef7876340a917876bc40df9cdde9232204125a75 100644
> --- a/fs/fs_parser.c
> +++ b/fs/fs_parser.c
> @@ -399,6 +399,9 @@ bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size,
> }
>
> for (i = 0; i < tbl_size; i++) {
> + if (!tbl[i].name && (i + 1 == tbl_size))
> + break;
> +
> if (!tbl[i].name) {
> pr_err("VALIDATE C-TBL[%zu]: Null\n", i);
> good = false;
> @@ -411,13 +414,13 @@ bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size,
> good = false;
> }
> if (c > 0) {
> - pr_err("VALIDATE C-TBL[%zu]: Missorted %s>=%s\n",
> + pr_err("VALIDATE C-TBL[%zu]: Missorted %s>%s\n",
> i, tbl[i-1].name, tbl[i].name);
> good = false;
> }
> }
>
> - if (tbl[i].value != special &&
> + if (tbl[i].name && tbl[i].value != special &&
> (tbl[i].value < low || tbl[i].value > high)) {
> pr_err("VALIDATE C-TBL[%zu]: %s->%d const out of range (%d-%d)\n",
> i, tbl[i].name, tbl[i].value, low, high);
>
> --
> 2.34.1
>
