On Wed, Oct 11, 2023 at 2:48 PM James Carter <jwcart2@xxxxxxxxx> wrote:
>
> On Mon, Aug 14, 2023 at 9:41 AM Christian Göttsche
> <cgzones@xxxxxxxxxxxxxx> wrote:
> >
> > Use fseek(3) instead of rewind(3) to detect failures.
> >
> > Drop the final rewind in digest_add_specfile(), since all callers are
> > going to close the stream without any further action.
> >
> > Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
>
> Acked-by: James Carter <jwcart2@xxxxxxxxx>
>
Merged.
Thanks,
Jim
> > ---
> > libselinux/src/is_customizable_type.c | 7 ++++++-
> > libselinux/src/label_backends_android.c | 5 ++++-
> > libselinux/src/label_file.c | 16 +++++++++++++---
> > libselinux/src/label_media.c | 5 ++++-
> > libselinux/src/label_support.c | 5 +++--
> > libselinux/src/label_x.c | 5 ++++-
> > 6 files changed, 34 insertions(+), 9 deletions(-)
> >
> > diff --git a/libselinux/src/is_customizable_type.c b/libselinux/src/is_customizable_type.c
> > index f83e1e83..9be50174 100644
> > --- a/libselinux/src/is_customizable_type.c
> > +++ b/libselinux/src/is_customizable_type.c
> > @@ -31,7 +31,12 @@ static void customizable_init(void)
> > while (fgets_unlocked(buf, selinux_page_size, fp) && ctr < UINT_MAX) {
> > ctr++;
> > }
> > - rewind(fp);
> > +
> > + if (fseek(fp, 0L, SEEK_SET) == -1) {
> > + fclose(fp);
> > + return;
> > + }
> > +
> > if (ctr) {
> > list =
> > (char **) calloc(sizeof(char *),
> > diff --git a/libselinux/src/label_backends_android.c b/libselinux/src/label_backends_android.c
> > index c2d78360..6494f3cd 100644
> > --- a/libselinux/src/label_backends_android.c
> > +++ b/libselinux/src/label_backends_android.c
> > @@ -208,7 +208,10 @@ static int init(struct selabel_handle *rec, const struct selinux_opt *opts,
> > goto finish;
> >
> > maxnspec = data->nspec;
> > - rewind(fp);
> > +
> > + status = fseek(fp, 0L, SEEK_SET);
> > + if (status == -1)
> > + goto finish;
> > }
> > }
> >
> > diff --git a/libselinux/src/label_file.c b/libselinux/src/label_file.c
> > index 471fd56b..a5677411 100644
> > --- a/libselinux/src/label_file.c
> > +++ b/libselinux/src/label_file.c
> > @@ -519,12 +519,16 @@ static char *rolling_append(char *current, const char *suffix, size_t max)
> > return current;
> > }
> >
> > -static bool fcontext_is_binary(FILE *fp)
> > +static int fcontext_is_binary(FILE *fp)
> > {
> > uint32_t magic;
> > + int rc;
> >
> > size_t len = fread(&magic, sizeof(magic), 1, fp);
> > - rewind(fp);
> > +
> > + rc = fseek(fp, 0L, SEEK_SET);
> > + if (rc == -1)
> > + return -1;
> >
> > return (len && (magic == SELINUX_MAGIC_COMPILED_FCONTEXT));
> > }
> > @@ -622,7 +626,13 @@ static int process_file(const char *path, const char *suffix,
> > if (fp == NULL)
> > return -1;
> >
> > - rc = fcontext_is_binary(fp) ?
> > + rc = fcontext_is_binary(fp);
> > + if (rc < 0) {
> > + (void) fclose(fp);
> > + return -1;
> > + }
> > +
> > + rc = rc ?
> > load_mmap(fp, sb.st_size, rec, found_path) :
> > process_text_file(fp, rec, found_path);
> > if (!rc)
> > diff --git a/libselinux/src/label_media.c b/libselinux/src/label_media.c
> > index f09461ab..b3443b47 100644
> > --- a/libselinux/src/label_media.c
> > +++ b/libselinux/src/label_media.c
> > @@ -130,7 +130,10 @@ static int init(struct selabel_handle *rec, const struct selinux_opt *opts,
> > goto finish;
> > memset(data->spec_arr, 0, sizeof(spec_t)*data->nspec);
> > maxnspec = data->nspec;
> > - rewind(fp);
> > +
> > + status = fseek(fp, 0L, SEEK_SET);
> > + if (status == -1)
> > + goto finish;
> > }
> > }
> > free(line_buf);
> > diff --git a/libselinux/src/label_support.c b/libselinux/src/label_support.c
> > index 94fb6697..f7ab9292 100644
> > --- a/libselinux/src/label_support.c
> > +++ b/libselinux/src/label_support.c
> > @@ -174,12 +174,13 @@ int digest_add_specfile(struct selabel_digest *digest, FILE *fp,
> > digest->hashbuf = tmp_buf;
> >
> > if (fp) {
> > - rewind(fp);
> > + if (fseek(fp, 0L, SEEK_SET) == -1)
> > + return -1;
> > +
> > if (fread(digest->hashbuf + (digest->hashbuf_size - buf_len),
> > 1, buf_len, fp) != buf_len)
> > return -1;
> >
> > - rewind(fp);
> > } else if (from_addr) {
> > tmp_buf = memcpy(digest->hashbuf +
> > (digest->hashbuf_size - buf_len),
> > diff --git a/libselinux/src/label_x.c b/libselinux/src/label_x.c
> > index e80bf107..e15190ca 100644
> > --- a/libselinux/src/label_x.c
> > +++ b/libselinux/src/label_x.c
> > @@ -157,7 +157,10 @@ static int init(struct selabel_handle *rec, const struct selinux_opt *opts,
> > goto finish;
> > memset(data->spec_arr, 0, sizeof(spec_t)*data->nspec);
> > maxnspec = data->nspec;
> > - rewind(fp);
> > +
> > + status = fseek(fp, 0L, SEEK_SET);
> > + if (status == -1)
> > + goto finish;
> > }
> > }
> > free(line_buf);
> > --
> > 2.40.1
> >
