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Fix make-fingerprint off-by-one bug

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Problem reported by Alex Gramiak in:
https://lists.gnu.org/r/emacs-devel/2019-04/msg00784.html
* lib-src/make-fingerprint.c (main): Fix recently-introduced
off-by-one bug when accessing args after -r.
This commit is contained in:
Paul Eggert 2019-04-18 12:56:23 -07:00
parent a99a3542f3
commit df5ca4f7e6
1 changed files with 13 additions and 12 deletions
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25
lib-src/make-fingerprint.c
View file

@ -80,24 +80,26 @@ main (int argc, char **argv)
struct sha256_ctx ctx;
sha256_init_ctx (&ctx);
char *prog = prog;
char *file = argv[optind];
if (argc - optind != 1)
{
fprintf (stderr, "%s: missing or extra file operand\n", argv[0]);
fprintf (stderr, "%s: missing or extra file operand\n", prog);
return EXIT_FAILURE;
}
FILE *f = fopen (argv[1], raw ? "r" FOPEN_BINARY : "r+" FOPEN_BINARY);
FILE *f = fopen (file, raw ? "r" FOPEN_BINARY : "r+" FOPEN_BINARY);
struct stat st;
if (!f || fstat (fileno (f), &st) != 0)
{
perror (argv[1]);
perror (file);
return EXIT_FAILURE;
}
if (!S_ISREG (st.st_mode))
{
fprintf (stderr, "%s: Error: %s is not a regular file\n",
argv[0], argv[1]);
prog, file);
return EXIT_FAILURE;
}
@ -105,7 +107,7 @@ main (int argc, char **argv)
min (SIZE_MAX, SSIZE_MAX));
if (maxlen <= st.st_size)
{
fprintf (stderr, "%s: %s: file too big\n", argv[0], argv[1]);
fprintf (stderr, "%s: %s: file too big\n", prog, file);
return EXIT_FAILURE;
}
@ -119,8 +121,7 @@ main (int argc, char **argv)
size_t chunksz = fread (buf, 1, st.st_size + 1, f);
if (ferror (f) || chunksz != st.st_size)
{
fprintf (stderr, "%s: Error: could not read %s\n",
argv[0], argv[1]);
fprintf (stderr, "%s: Error: could not read %s\n", prog, file);
return EXIT_FAILURE;
}
@ -139,33 +140,33 @@ main (int argc, char **argv)
char *finger = memmem (buf, chunksz, fingerprint, sizeof fingerprint);
if (!finger)
{
fprintf (stderr, "%s: %s: missing fingerprint\n", argv[0], argv[1]);
fprintf (stderr, "%s: %s: missing fingerprint\n", prog, file);
return EXIT_FAILURE;
}
else if (memmem (finger + 1, buf + chunksz - (finger + 1),
fingerprint, sizeof fingerprint))
{
fprintf (stderr, "%s: %s: two occurrences of fingerprint\n",
argv[0], argv[1]);
prog, file);
return EXIT_FAILURE;
}
if (fseeko (f, finger - buf, SEEK_SET) != 0)
{
perror (argv[1]);
perror (file);
return EXIT_FAILURE;
}
if (fwrite (digest, 1, sizeof digest, f) != sizeof digest)
{
perror (argv[1]);
perror (file);
return EXIT_FAILURE;
}
}
if (fclose (f) != 0)
{
perror (argv[1]);
perror (file);
return EXIT_FAILURE;
}