From 7add441984063d2c34fa8de252b8ceb803e7981a Mon Sep 17 00:00:00 2001 From: Jeff King Date: Mon, 8 Dec 2014 00:48:13 -0500 Subject: [PATCH] fsck: properly bound "invalid tag name" error message When we detect an invalid tag-name header in a tag object, like, "tag foo bar\n", we feed the pointer starting at "foo bar" to a printf "%s" formatter. This shows the name, as we want, but then it keeps printing the rest of the tag buffer, rather than stopping at the end of the line. Our tests did not notice because they look only for the matching line, but the bug is that we print much more than we wanted to. So we also adjust the test to be more exact. Note that when fscking tags with "index-pack --strict", this is even worse. index-pack does not add a trailing NUL-terminator after the object, so we may actually read past the buffer and print uninitialized memory. Running t5302 with valgrind does notice the bug for that reason. Signed-off-by: Jeff King Acked-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- fsck.c | 3 ++- t/t1450-fsck.sh | 8 ++++++-- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/fsck.c b/fsck.c index 2fffa434a5..88c92e82d1 100644 --- a/fsck.c +++ b/fsck.c @@ -423,7 +423,8 @@ static int fsck_tag_buffer(struct tag *tag, const char *data, } strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer); if (check_refname_format(sb.buf, 0)) - error_func(&tag->object, FSCK_WARN, "invalid 'tag' name: %s", buffer); + error_func(&tag->object, FSCK_WARN, "invalid 'tag' name: %.*s", + (int)(eol - buffer), buffer); buffer = eol + 1; if (!skip_prefix(buffer, "tagger ", &buffer)) diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh index 1b96b4045b..7850607783 100755 --- a/t/t1450-fsck.sh +++ b/t/t1450-fsck.sh @@ -209,8 +209,12 @@ test_expect_success 'tag with incorrect tag name & missing tagger' ' echo $tag >.git/refs/tags/wrong && test_when_finished "git update-ref -d refs/tags/wrong" && git fsck --tags 2>out && - grep "invalid .tag. name" out && - grep "expected .tagger. line" out + + cat >expect <<-EOF && + warning in tag $tag: invalid '\''tag'\'' name: wrong name format + warning in tag $tag: invalid format - expected '\''tagger'\'' line + EOF + test_cmp expect out ' test_expect_success 'cleaned up' '