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Re: [PATCHv3 1/4] notes: don't leak memory in git_config_get_notes_strategy

From
Junio C Hamano <gitster@pobox.com>
Date
Mar 31, 2016, 22:54 UTC
Message-ID
<xmqq7fgil0lu.fsf@gitster.mtv.corp.google.com>
In-Reply-To
<CAPig+cRPNt1aNdsONXgX0SkgNiYtTS8vCGQzE2u4+vpd-N-Vew@mail.gmail.com>
Eric Sunshine <sunshine@sunshineco.com> writes:
Show 30 quoted lines
> On Thu, Mar 31, 2016 at 2:04 PM, Stefan Beller <sbeller@google.com> wrote:
>> `value` is just a temporary scratchpad, so we need to make sure it doesn't
>> leak. It is xstrdup'd in `git_config_get_string_const` and
>> `parse_notes_merge_strategy` just compares the string against predefined
>> values, so no need to keep it around longer. Instead of using
>> `git_config_get_string_const`, use `git_config_get_value`, which doesn't
>> return a copy.
>>
>> Signed-off-by: Stefan Beller <sbeller@google.com>
>> ---
>> diff --git a/builtin/notes.c b/builtin/notes.c
>> @@ -746,7 +746,7 @@ static int git_config_get_notes_strategy(const char *key,
>>  {
>>         const char *value;
>>
>> -       if (git_config_get_string_const(key, &value))
>> +       if (git_config_get_value(key, &value))
>
> Hmm, doesn't this introduce a rather severe regression? Unless I'm
> misreading the code (possible), with the original, if 'key' was
> boolean (lacked a value in the config file), then it would complain:
>
>     Missing value for 'floop.blork'
>
> but, with this change, it will dereference NULL and crash.
>
> (My understanding was that Peff's suggestion to use
> git_config_get_value() implied a bit of work beyond the simple textual
> substitution of 'git_config_get_value' for
> 'git_config_get_string_const'.)
Yup, thanks for spelling it out.
Previous: Eric SunshineNext: Jeff King
Message 4 of 13 in “[PATCHv3 0/4] Some cleanups”
  1. Stefan BellerMar 31, 2016
  2. 1/4 notes: don't leak memory in git_config_get_notes_strategyStefan Beller, Mar 31, 2016
  3. Eric SunshineMar 31, 2016
  4. Junio C HamanoMar 31, 2016
  5. Jeff KingMar 31, 2016
  6. 2/4 abbrev_sha1_in_line: don't leak memoryStefan Beller, Mar 31, 2016
  7. 3/4 bundle: don't leak an fd in case of early returnStefan Beller, Mar 31, 2016
  8. Jeff KingMar 31, 2016
  9. 4/4 credential-cache, send_request: close fd when doneStefan Beller, Mar 31, 2016
  10. Jeff KingMar 31, 2016
  11. Junio C HamanoMar 31, 2016
  12. Jeff KingMar 31, 2016
  13. Junio C HamanoMar 31, 2016

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