[PATCH 1/6] receive-pack: fix deadlock when we cannot create tmpdir
- From
Jeff King <peff@peff.net>
- Date
- Mar 7, 2017, 13:35 UTC
- Message-ID
- <20170307133534.bgar57ojq52snns3@sigill.intra.peff.net>
- In-Reply-To
- <20170307133437.qee2jtynbiwf6uzr@sigill.intra.peff.net>
The err_fd descriptor passed to the unpack() function is intended to be handed off to the child index-pack, and our async muxer will read until it gets EOF. However, if we encounter an error before handing off the descriptor, we must manually close(err_fd). Otherwise we will be waiting for our muxer to finish, while the muxer is waiting for EOF on err_fd.
We fixed an identical deadlock already in 49ecfa13f (receive-pack: close sideband fd on early pack errors, 2013-04-19). But since then, the function grew a new early-return in 722ff7f87 (receive-pack: quarantine objects until pre-receive accepts, 2016-10-03), when we fail to create a temporary directory. This return needs the same treatment.
Reported-by: Horst Schirmeier <horst@schirmeier.com> Signed-off-by: Jeff King <peff@peff.net> --- builtin/receive-pack.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c index 9ed8fbbfa..f2c6953a3 100644 --- a/builtin/receive-pack.c +++ b/builtin/receive-pack.c @@ -1667,8 +1667,11 @@ static const char *unpack(int err_fd, struct shallow_info *si) } tmp_objdir = tmp_objdir_create(); - if (!tmp_objdir) + if (!tmp_objdir) { + if (err_fd > 0) + close(err_fd); return "unable to create temporary object directory"; + } child.env = tmp_objdir_env(tmp_objdir); /*
-- 2.12.0.429.gde83c8049