The char array named "buffer" is unlikely to contain a NUL character, so
printing its contents using %s in a die() format is unsafe.  Clang's
ASan reports running over the end of buffer in the recently added
skiplist tests in t5504-fetch-receive-strict.sh as a result.

Use an idiomatic strbuf_getline() loop instead, which ensures the buffer
is always NUL-terminated.  As a side-effect this also adds support for
skiplist files with CRLF line endings.

Signed-off-by: Rene Scharfe <l....@web.de>
---
 fsck.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/fsck.c b/fsck.c
index a0cee0be59..83f4562390 100644
--- a/fsck.c
+++ b/fsck.c
@@ -183,8 +183,9 @@ static int fsck_msg_type(enum fsck_msg_id msg_id,
 static void init_skiplist(struct fsck_options *options, const char *path)
 {
        static struct oid_array skiplist = OID_ARRAY_INIT;
-       int sorted, fd;
-       char buffer[GIT_MAX_HEXSZ + 1];
+       int sorted;
+       FILE *fp;
+       struct strbuf sb = STRBUF_INIT;
        struct object_id oid;
if (options->skiplist)
@@ -194,25 +195,21 @@ static void init_skiplist(struct fsck_options *options, 
const char *path)
                options->skiplist = &skiplist;
        }
- fd = open(path, O_RDONLY);
-       if (fd < 0)
+       fp = fopen(path, "r");
+       if (!fp)
                die("Could not open skip list: %s", path);
-       for (;;) {
+       while (!strbuf_getline(&sb, fp)) {
                const char *p;
-               int result = read_in_full(fd, buffer, sizeof(buffer));
-               if (result < 0)
-                       die_errno("Could not read '%s'", path);
-               if (!result)
-                       break;
-               if (parse_oid_hex(buffer, &oid, &p) || *p != '\n')
-                       die("Invalid SHA-1: %s", buffer);
+               if (parse_oid_hex(sb.buf, &oid, &p) || *p != '\0')
+                       die("Invalid SHA-1: %s", sb.buf);
                oid_array_append(&skiplist, &oid);
                if (sorted && skiplist.nr > 1 &&
                                oidcmp(&skiplist.oid[skiplist.nr - 2],
                                       &oid) > 0)
                        sorted = 0;
        }
-       close(fd);
+       fclose(fp);
+       strbuf_release(&sb);
if (sorted)
                skiplist.sorted = 1;
--
2.18.0

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