From 974da80e08d24e92e5409bb040f95d06a47776a2 Mon Sep 17 00:00:00 2001 From: James Carter Date: Fri, 8 Oct 2021 10:27:49 -0400 Subject: [PATCH] libsepol/cil: Fix potential undefined shifts An expression of the form "1 << x" is undefined if x == 31 because the "1" is an int and cannot be left shifted by 31. Instead, use "UINT32_C(1) << x" which will be an unsigned int of at least 32 bits. This bug was found by the secilc-fuzzer. Signed-off-by: James Carter --- libsepol/cil/src/cil_binary.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/libsepol/cil/src/cil_binary.c b/libsepol/cil/src/cil_binary.c index ec5f01e..d8aa495 100644 --- a/libsepol/cil/src/cil_binary.c +++ b/libsepol/cil/src/cil_binary.c @@ -1225,7 +1225,7 @@ int __perm_str_to_datum(char *perm_str, class_datum_t *sepol_class, uint32_t *da goto exit; } } - *datum |= 1 << (sepol_perm->s.value - 1); + *datum |= UINT32_C(1) << (sepol_perm->s.value - 1); return SEPOL_OK; @@ -1523,7 +1523,7 @@ int cil_avrule_to_policydb(policydb_t *pdb, const struct cil_db *db, struct cil_ /* index of the u32 containing the permission */ #define XPERM_IDX(x) (x >> 5) /* set bits 0 through x-1 within the u32 */ -#define XPERM_SETBITS(x) ((1U << (x & 0x1f)) - 1) +#define XPERM_SETBITS(x) ((UINT32_C(1) << (x & 0x1f)) - 1) /* low value for this u32 */ #define XPERM_LOW(x) (x << 5) /* high value for this u32 */ @@ -4760,7 +4760,7 @@ static struct cil_list *cil_classperms_from_sepol(policydb_t *pdb, uint16_t clas cil_list_init(&cp->perms, CIL_PERM); for (i = 0; i < sepol_class->permissions.nprim; i++) { struct cil_perm *perm; - if ((data & (1 << i)) == 0) continue; + if ((data & (UINT32_C(1) << i)) == 0) continue; perm = perm_value_to_cil[class][i+1]; if (!perm) goto exit; cil_list_append(cp->perms, CIL_PERM, perm); -- 1.8.3.1