Re: [PATCH] sequencer: detect author name errors in read_author_script()
- From
Jeff King <peff@peff.net>
- Date
- Oct 3, 2022, 17:35 UTC
- Message-ID
- <YzsdRuD2CdJFdNVG@coredump.intra.peff.net>
- In-Reply-To
- <YzqhEcTDwMwa8dQX@coredump.intra.peff.net>
On Mon, Oct 03, 2022 at 04:45:06AM -0400, Jeff King wrote:
Show 9 quoted lines
> > I haven't been able to actually trigger the bug, but strongly suspect > > I'm just not familiar enough with how rebasing works under the covers. > > It's a little tricky, because we avoid writing and reading the > author-script file unless necessary. An easy way to need it is to break > with a conflict (which writes it), and then resume with "git rebase > --continue" (which reads it back while committing). > > Here's a patch to fix it. Thanks for your report!
And here's a v2 based on the feedback received. The one-liner fix is the same, but it tries to be a little less clever when constructing the tests and has 200% more typo fixes in the commit message. Thanks Phillip and Ævar for review.
-- >8 -- Subject: [PATCH] sequencer: detect author name errors in read_author_script()
As we parse the author-script file, we check for missing or duplicate lines for GIT_AUTHOR_NAME, etc. But after reading the whole file, our final error conditional checks "date_i" twice and "name_i" not at all. This not only leads to us failing to abort, but we may do an out-of-bounds read on the string_list array.
The bug goes back to 442c36bd08 (am: improve author-script error reporting, 2018-10-31), though the code was soon after moved to this spot by bcd33ec25f (add read_author_script() to libgit, 2018-10-31). It was presumably just a typo in 442c36bd08.
We'll add test coverage for all the error cases here, though only the GIT_AUTHOR_NAME ones fail (even in a vanilla build they segfault consistently, but certainly with SANITIZE=address).
Reported-by: Michael V. Scovetta <michael.scovetta@gmail.com> Signed-off-by: Jeff King <peff@peff.net> --- sequencer.c | 2 +- t/t3438-rebase-broken-files.sh | 59 ++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+), 1 deletion(-) create mode 100755 t/t3438-rebase-broken-files.sh
diff --git a/sequencer.c b/sequencer.c index d26ede83c4..83e0425b04 100644 --- a/sequencer.c +++ b/sequencer.c @@ -915,7 +915,7 @@ int read_author_script(const char *path, char **name, char **email, char **date, error(_("missing 'GIT_AUTHOR_EMAIL'")); if (date_i == -2) error(_("missing 'GIT_AUTHOR_DATE'")); - if (date_i < 0 || email_i < 0 || date_i < 0 || err) + if (name_i < 0 || email_i < 0 || date_i < 0 || err) goto finish; *name = kv.items[name_i].util; *email = kv.items[email_i].util; diff --git a/t/t3438-rebase-broken-files.sh b/t/t3438-rebase-broken-files.sh new file mode 100755 index 0000000000..b92a3ce46b --- /dev/null +++ b/t/t3438-rebase-broken-files.sh @@ -0,0 +1,59 @@ +#!/bin/sh + +test_description='rebase behavior when on-disk files are broken' +. ./test-lib.sh + +test_expect_success 'set up conflicting branches' ' + test_commit base file && + git checkout -b branch1 && + test_commit one file && + git checkout -b branch2 HEAD^ && + test_commit two file +' + +create_conflict () { + test_when_finished "git rebase --abort" && + git checkout -B tmp branch2 && + test_must_fail git rebase branch1 +} + +check_resolve_fails () { + echo resolved >file && + git add file && + test_must_fail git rebase --continue +} + +for item in NAME EMAIL DATE +do + test_expect_success "detect missing GIT_AUTHOR_$item" ' + create_conflict && + + grep -v $item .git/rebase-merge/author-script >tmp && + mv tmp .git/rebase-merge/author-script && + + check_resolve_fails + ' +done + +for item in NAME EMAIL DATE +do + test_expect_success "detect duplicate GIT_AUTHOR_$item" ' + create_conflict && + + grep -i $item .git/rebase-merge/author-script >tmp && + cat tmp >>.git/rebase-merge/author-script && + + check_resolve_fails + ' +done + +test_expect_success 'unknown key in author-script' ' + create_conflict && + + echo "GIT_AUTHOR_BOGUS=${SQ}whatever${SQ}" \ + >>.git/rebase-merge/author-script && + + check_resolve_fails +' + +test_done
-- 2.38.0.rc2.659.g50b8df2659