| Message ID | 20211008211031.393884-2-jwcart2@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [1/4] libsepol: Fix potential undefined shifts | expand |
On Fri, Oct 8, 2021 at 11:10 PM James Carter <jwcart2@gmail.com> wrote: > > 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 <jwcart2@gmail.com> > --- > 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 ec5f01e5..34dc63c7 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) There is a missing parenthesis here: "UINT32_C(1)" -> "(UINT32_C(1)" Other than this, the 4 patches look good to me: Acked-by: Nicolas Iooss <nicolas.iooss@m4x.org> Thanks! Nicolas > /* 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); > -- > 2.31.1 >
On Sun, Oct 10, 2021 at 4:40 PM Nicolas Iooss <nicolas.iooss@m4x.org> wrote: > > On Fri, Oct 8, 2021 at 11:10 PM James Carter <jwcart2@gmail.com> wrote: > > > > 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 <jwcart2@gmail.com> > > --- > > 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 ec5f01e5..34dc63c7 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) > > There is a missing parenthesis here: "UINT32_C(1)" -> "(UINT32_C(1)" > > Other than this, the 4 patches look good to me: > > Acked-by: Nicolas Iooss <nicolas.iooss@m4x.org> > I fixed the missing parenthesis and merged these patches. Thanks, Jim > Thanks! > Nicolas > > > /* 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); > > -- > > 2.31.1 > > >
diff --git a/libsepol/cil/src/cil_binary.c b/libsepol/cil/src/cil_binary.c index ec5f01e5..34dc63c7 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);
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 <jwcart2@gmail.com> --- libsepol/cil/src/cil_binary.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)