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-rw-r--r--coreutils/uudecode.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/coreutils/uudecode.c b/coreutils/uudecode.c
index 751976a..10e5a55 100644
--- a/coreutils/uudecode.c
+++ b/coreutils/uudecode.c
@@ -286,13 +286,19 @@ int baseNUM_main(int argc UNUSED_PARAM, char **argv)
} else {
enum {
SRC_BUF_SIZE = 3 * 5 * 32, /* this *MUST* be a multiple of 3 and 5 */
- DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
+ DST_BUF_SIZE = 8 * ((SRC_BUF_SIZE + 4) / 5), /* max growth on decode (base32 case) */
};
- char src_buf[SRC_BUF_SIZE];
- char dst_buf[DST_BUF_SIZE + 1];
- int src_fd = fileno(src_stream);
- int rem = 0;
+ /* Use one buffer for both input and output:
+ * decoding reads input "left-to-right",
+ * it's safe to place source at the end of the buffer and
+ * overwrite it while decoding, just be careful to have a gap.
+ */
+ char dst_buf[((DST_BUF_SIZE + /*gap:*/ 16) /*round up to 16:*/ | 0xf) + 1];
+#define src_buf (dst_buf + sizeof(dst_buf) - SRC_BUF_SIZE)
+ int src_fd, rem;
+ src_fd = fileno(src_stream);
+ rem = 0;
while (1) {
size_t size = full_read(src_fd, src_buf, SRC_BUF_SIZE);
if ((ssize_t)size < 0)
@@ -331,6 +337,7 @@ int baseNUM_main(int argc UNUSED_PARAM, char **argv)
}
}
}
+#undef src_buf
}
fflush_stdout_and_exit(EXIT_SUCCESS);