From: Eric Sunshine Date: Tue, 31 Jul 2018 07:33:28 +0000 (-0400) Subject: sequencer: fix "rebase -i --root" corrupting author header X-Git-Tag: v2.19.0-rc0~55^2~3 X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/ca3e1826a063ff7576a5e134f3b20b68196a1a5d?hp=53f9a3e157dbbc901a02ac2c73346d375e24978c sequencer: fix "rebase -i --root" corrupting author header When "git rebase -i --root" creates a new root commit (say, by swapping in a different commit for the root), it corrupts the commit's "author" header with trailing garbage: author A U Thor @1112912773 -07000or@example.com This is a result of read_author_ident() neglecting to NUL-terminate the buffer into which it composes the "author" header. (Note that the "@" preceding the timestamp and the extra "0" in the timezone are separate bugs which will be fixed subsequently.) Security considerations: Construction of the "author" header by read_author_ident() happens in-place and in parallel with parsing the content of "rebase-merge/author-script" which occupies the same buffer. This is possible because the constructed "author" header is always smaller than the content of "rebase-merge/author-script". Despite neglecting to NUL-terminate the constructed "author" header, memory is never accessed (either by read_author_ident() or its caller) beyond the allocated buffer since a NUL-terminator is present at the end of the loaded "rebase-merge/author-script" content, and additional NUL's are inserted as part of the parsing process. Signed-off-by: Eric Sunshine Acked-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- diff --git a/sequencer.c b/sequencer.c index 4034c0461b..df11136f9d 100644 --- a/sequencer.c +++ b/sequencer.c @@ -741,7 +741,7 @@ static const char *read_author_ident(struct strbuf *buf) return NULL; } - buf->len = out - buf->buf; + strbuf_setlen(buf, out - buf->buf); return buf->buf; } diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh index 352a52e59d..347a09502e 100755 --- a/t/t3404-rebase-interactive.sh +++ b/t/t3404-rebase-interactive.sh @@ -1202,7 +1202,7 @@ rebase_setup_and_clean () { test_might_fail git branch -D $1 && test_might_fail git rebase --abort " && - git checkout -b $1 master + git checkout -b $1 ${2:-master} } test_expect_success 'drop' ' @@ -1379,4 +1379,12 @@ test_expect_success 'rebase -i --gpg-sign= overrides commit.gpgSign' ' test_i18ngrep "$SQ-S\"S I Gner\"$SQ" err ' +test_expect_success 'valid author header after --root swap' ' + rebase_setup_and_clean author-header no-conflict-branch && + set_fake_editor && + FAKE_LINES="2 1" git rebase -i --root && + git cat-file commit HEAD^ >out && + grep "^author ..*> @[0-9][0-9]* [-+][0-9][0-9]*$" out +' + test_done