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Re: [PATCH 3/5] resolv: Fix file handle leak in __resolv_conf_load [BZ #25429]
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: Florian Weimer <fweimer at redhat dot com>
- Cc: libc-alpha at sourceware dot org
- Date: Thu, 13 Feb 2020 18:30:09 -0300
- Subject: Re: [PATCH 3/5] resolv: Fix file handle leak in __resolv_conf_load [BZ #25429]
- References: <cover.1579631655.git.fweimer@redhat.com> <4d8628bf1d8630c16de30d47732058ec82293429.1579631655.git.fweimer@redhat.com> <dd59f273-a62f-114a-b718-57a0ac74567f@linaro.org> <871rqy5h64.fsf@oldenburg2.str.redhat.com>
On 13/02/2020 18:08, Florian Weimer wrote:
> * Adhemerval Zanella:
>
>> On 21/01/2020 15:41, Florian Weimer wrote:
>>> res_vinit_1 did not close the stream on errors, only on success.
>>> This change moves closing the stream to __resolv_conf_load, for both
>>> the success and error cases.
>>>
>>> Fixes commit 89f187a40fc0ad4e22838526bfe34d73f758b776 ("resolv: Use
>>> getline for configuration file reading in res_vinit_1") and commit
>>> 3f853f22c87f0b671c0366eb290919719fa56c0e ("resolv: Lift domain search
>>> list limits [BZ #19569] [BZ #21475]"), where memory allocation was
>>> introduced into res_vinit_1.
>>> ---
>>> resolv/res_init.c | 8 +++++++-
>>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/resolv/res_init.c b/resolv/res_init.c
>>> index 95dce098aa..09345718cd 100644
>>> --- a/resolv/res_init.c
>>> +++ b/resolv/res_init.c
>>> @@ -508,7 +508,6 @@ res_vinit_1 (FILE *fp, struct resolv_conf_parser *parser)
>>> continue;
>>> }
>>> }
>>> - fclose (fp);
>>> }
>>> if (__glibc_unlikely (nameserver_list_size (&parser->nameserver_list) == 0))
>>> {
>>> @@ -593,6 +592,13 @@ __resolv_conf_load (struct __res_state *preinit)
>>> }
>>> resolv_conf_parser_free (&parser);
>>>
>>> + if (fp != NULL)
>>> + {
>>> + int saved_errno = errno;
>>> + fclose (fp);
>>> + __set_errno (saved_errno);
>>> + }
>>> +
>>> return conf;
>>> }
>>
>> Why not close the FILE on __resolv_conf_load? It make the FILE object
>> cleanup as close as its creation, which usually improves readability.
>
> Sorry, I don't understand. Isn't this what the patch does?
Nevermind, for some reason I though it was doing on res_vinit_1.
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>