On Tue, Jan 25, 2022 at 6:14 AM Christian Göttsche
<cgzones@xxxxxxxxxxxxxx> wrote:
>
> Enclose the macro arguments in parenthesis to avoid potential evaluation
> order issues.
>
> Note the xperm and ebitmap macros are still not side-effect safe due to
> double evaluation.
>
> Reported by clang-tidy [bugprone-macro-parentheses]
Good idea to run clang-tidy :)
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
>
> Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
> ---
> security/selinux/include/security.h | 4 ++--
> security/selinux/ss/ebitmap.h | 6 +++---
> security/selinux/ss/sidtab.c | 4 ++--
> 3 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
> index 6482e0efb368..d91a5672de99 100644
> --- a/security/selinux/include/security.h
> +++ b/security/selinux/include/security.h
> @@ -254,8 +254,8 @@ struct av_decision {
> #define XPERMS_AUDITALLOW 2
> #define XPERMS_DONTAUDIT 4
>
> -#define security_xperm_set(perms, x) (perms[x >> 5] |= 1 << (x & 0x1f))
> -#define security_xperm_test(perms, x) (1 & (perms[x >> 5] >> (x & 0x1f)))
> +#define security_xperm_set(perms, x) ((perms)[(x) >> 5] |= 1 << ((x) & 0x1f))
> +#define security_xperm_test(perms, x) (1 & ((perms)[(x) >> 5] >> ((x) & 0x1f)))
> struct extended_perms_data {
> u32 p[8];
> };
> diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h
> index 9eb2d0af2805..58eb822f11ee 100644
> --- a/security/selinux/ss/ebitmap.h
> +++ b/security/selinux/ss/ebitmap.h
> @@ -118,9 +118,9 @@ static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
> }
>
> #define ebitmap_for_each_positive_bit(e, n, bit) \
> - for (bit = ebitmap_start_positive(e, &n); \
> - bit < ebitmap_length(e); \
> - bit = ebitmap_next_positive(e, &n, bit)) \
> + for ((bit) = ebitmap_start_positive(e, &(n)); \
> + (bit) < ebitmap_length(e); \
> + (bit) = ebitmap_next_positive(e, &(n), bit)) \
>
> int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
> int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
> diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
> index 293ec048af08..a54b8652bfb5 100644
> --- a/security/selinux/ss/sidtab.c
> +++ b/security/selinux/ss/sidtab.c
> @@ -27,8 +27,8 @@ struct sidtab_str_cache {
> char str[];
> };
>
> -#define index_to_sid(index) (index + SECINITSID_NUM + 1)
> -#define sid_to_index(sid) (sid - (SECINITSID_NUM + 1))
> +#define index_to_sid(index) ((index) + SECINITSID_NUM + 1)
> +#define sid_to_index(sid) ((sid) - (SECINITSID_NUM + 1))
>
> int sidtab_init(struct sidtab *s)
> {
> --
> 2.34.1
>
--
Thanks,
~Nick Desaulniers
