| Message ID | 20220408131054.7957-4-cgzones@googlemail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 0aa974a439c6 |
| Headers | show |
| Series | [1/5] libsepol/cil: declare file local function pointer static | expand |
On Fri, 8 Apr 2022 at 15:10, Christian Göttsche <cgzones@googlemail.com> wrote: > > The `struct selabel_digest` member `hashbuf_size` is used to compute > hashes via `Sha1Update()`, which takes uint32_t as length parameter > type. Use that same type for `hashbuf_size` to avoid potential value > truncations, as the overflow check in `digest_add_specfile()` on > `hashbuf_size` is based on it. > > label_support.c: In function ‘digest_gen_hash’: > label_support.c:125:53: warning: conversion from ‘size_t’ {aka ‘long unsigned int’} to ‘uint32_t’ {aka ‘unsigned int’} may change value [-Wconversion] > 125 | Sha1Update(&context, digest->hashbuf, digest->hashbuf_size); > | ~~~~~~^~~~~~~~~~~~~~ An alternative would be to split the `Sha1Update()` call[1] into multiple, each for a maximum of UINT32_MAX bytes. [1]: https://github.com/SELinuxProject/selinux/blob/73562de8fc70b21aeb6be86dfdfddb7502d236ea/libselinux/src/label_support.c#L125 > Signed-off-by: Christian Göttsche <cgzones@googlemail.com> > --- > libselinux/src/label_internal.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/libselinux/src/label_internal.h b/libselinux/src/label_internal.h > index 782c6aa8..82a762f7 100644 > --- a/libselinux/src/label_internal.h > +++ b/libselinux/src/label_internal.h > @@ -57,7 +57,7 @@ int selabel_service_init(struct selabel_handle *rec, > struct selabel_digest { > unsigned char *digest; /* SHA1 digest of specfiles */ > unsigned char *hashbuf; /* buffer to hold specfiles */ > - size_t hashbuf_size; /* buffer size */ > + uint32_t hashbuf_size; /* buffer size */ > size_t specfile_cnt; /* how many specfiles processed */ > char **specfile_list; /* and their names */ > }; > -- > 2.35.1 >
diff --git a/libselinux/src/label_internal.h b/libselinux/src/label_internal.h index 782c6aa8..82a762f7 100644 --- a/libselinux/src/label_internal.h +++ b/libselinux/src/label_internal.h @@ -57,7 +57,7 @@ int selabel_service_init(struct selabel_handle *rec, struct selabel_digest { unsigned char *digest; /* SHA1 digest of specfiles */ unsigned char *hashbuf; /* buffer to hold specfiles */ - size_t hashbuf_size; /* buffer size */ + uint32_t hashbuf_size; /* buffer size */ size_t specfile_cnt; /* how many specfiles processed */ char **specfile_list; /* and their names */ };
The `struct selabel_digest` member `hashbuf_size` is used to compute hashes via `Sha1Update()`, which takes uint32_t as length parameter type. Use that same type for `hashbuf_size` to avoid potential value truncations, as the overflow check in `digest_add_specfile()` on `hashbuf_size` is based on it. label_support.c: In function ‘digest_gen_hash’: label_support.c:125:53: warning: conversion from ‘size_t’ {aka ‘long unsigned int’} to ‘uint32_t’ {aka ‘unsigned int’} may change value [-Wconversion] 125 | Sha1Update(&context, digest->hashbuf, digest->hashbuf_size); | ~~~~~~^~~~~~~~~~~~~~ Signed-off-by: Christian Göttsche <cgzones@googlemail.com> --- libselinux/src/label_internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)