From: Christian Göttsche <cgzones@xxxxxxxxxxxxxx> Avoid using nontransitive comparison to prevent unexpected sorting results due to (well-defined) overflows. See https://www.qualys.com/2024/01/30/qsort.txt for a related issue in glibc's qsort(3). Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx> --- security/selinux/ss/policydb.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 383f3ae82a73..d04d9ada3835 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -37,6 +37,8 @@ #include "mls.h" #include "services.h" +#define spaceship_cmp(a, b) (((a) > (b)) - ((a) < (b))) + #ifdef CONFIG_SECURITY_SELINUX_DEBUG /* clang-format off */ static const char *const symtab_name[SYM_NUM] = { @@ -421,11 +423,11 @@ static int filenametr_cmp(const void *k1, const void *k2) const struct filename_trans_key *ft2 = k2; int v; - v = ft1->ttype - ft2->ttype; + v = spaceship_cmp(ft1->ttype, ft2->ttype); if (v) return v; - v = ft1->tclass - ft2->tclass; + v = spaceship_cmp(ft1->tclass, ft2->tclass); if (v) return v; @@ -456,15 +458,15 @@ static int rangetr_cmp(const void *k1, const void *k2) const struct range_trans *key1 = k1, *key2 = k2; int v; - v = key1->source_type - key2->source_type; + v = spaceship_cmp(key1->source_type, key2->source_type); if (v) return v; - v = key1->target_type - key2->target_type; + v = spaceship_cmp(key1->target_type, key2->target_type); if (v) return v; - v = key1->target_class - key2->target_class; + v = spaceship_cmp(key1->target_class, key2->target_class); return v; } @@ -493,15 +495,15 @@ static int role_trans_cmp(const void *k1, const void *k2) const struct role_trans_key *key1 = k1, *key2 = k2; int v; - v = key1->role - key2->role; + v = spaceship_cmp(key1->role, key2->role); if (v) return v; - v = key1->type - key2->type; + v = spaceship_cmp(key1->type, key2->type); if (v) return v; - return key1->tclass - key2->tclass; + return spaceship_cmp(key1->tclass, key2->tclass); } static const struct hashtab_key_params roletr_key_params = { -- 2.45.2
