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From: Jeff King <peff@peff.net>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org, Michael Haggerty <mhagger@alum.mit.edu>
Subject: [PATCH v4 0/3] fix corner cases with lock_ref_sha1_basic
Date: Tue, 12 Jan 2016 16:43:18 -0500	[thread overview]
Message-ID: <20160112214318.GA2527@sigill.intra.peff.net> (raw)
In-Reply-To: <20160112204229.GA13706@sigill.intra.peff.net>

On Tue, Jan 12, 2016 at 03:42:29PM -0500, Jeff King wrote:

> Ah, I see. When calling git-symbolic-ref, we don't provide an old_sha1,
> and therefore never call verify_lock(). And we get whatever value in
> lock->old_oid we happened to read earlier in resolve_ref_unsafe(). Which
> happened outside of a lock. Yikes. It seems like we could racily write
> the wrong reflog entry in such a case.
>
> [...]
> The patch above is not quite right; I'll work up a series that takes
> this approach.

OK, here it is. This replaces the top two patches of jk/symbolic-ref
(i.e., everything in this thread I've sent in the last day or two).

Besides fixing the race (which is detailed in patch 2/3), I think the
resulting 3/3 is much cleaner. Sorry for all the false starts. The more
I looked at this, the more complex it seemed to get. But I _think_ this
is the right solution. :)

  [1/3]: checkout,clone: check return value of create_symref
  [2/3]: lock_ref_sha1_basic: always fill old_oid while holding lock
  [3/3]: lock_ref_sha1_basic: handle REF_NODEREF with invalid refs

-Peff

  reply	other threads:[~2016-01-12 21:43 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-11 15:46 [PATCH 0/2] fix corner case with lock_ref_sha1_basic and REF_NODEREF Jeff King
2016-01-11 15:49 ` [PATCH 1/2] checkout,clone: check return value of create_symref Jeff King
2016-01-12  4:09   ` Michael Haggerty
2016-01-12  9:49     ` Jeff King
2016-01-11 15:52 ` [PATCH 2/2] lock_ref_sha1_basic: handle REF_NODEREF with invalid refs Jeff King
2016-01-11 18:28   ` Junio C Hamano
2016-01-12  4:55   ` Michael Haggerty
2016-01-12  9:52     ` Jeff King
2016-01-12 18:11       ` Junio C Hamano
2016-01-12  9:56 ` [PATCH v2 0/2] fix corner case with lock_ref_sha1_basic and REF_NODEREF Jeff King
2016-01-12  9:57   ` [PATCH v2 1/2] checkout,clone: check return value of create_symref Jeff King
2016-01-12  9:58   ` [PATCH v2 2/2] lock_ref_sha1_basic: handle REF_NODEREF with invalid refs Jeff King
2016-01-12 13:26     ` Jeff King
2016-01-12 13:55       ` [PATCH v3 " Jeff King
2016-01-12 19:41         ` Junio C Hamano
2016-01-12 20:22           ` Jeff King
2016-01-12 20:42             ` Jeff King
2016-01-12 21:43               ` Jeff King [this message]
2016-01-12 21:44                 ` [PATCH 1/3] checkout,clone: check return value of create_symref Jeff King
2016-01-12 21:44                 ` [PATCH 2/3] lock_ref_sha1_basic: always fill old_oid while holding lock Jeff King
2016-01-13  1:25                   ` Eric Sunshine
2016-01-13 11:38                     ` Jeff King
2016-01-12 21:45                 ` [PATCH 3/3] lock_ref_sha1_basic: handle REF_NODEREF with invalid refs Jeff King

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