threads / discuss / 32786

Segmentation fault with latest git (070c57df)

Subject: Segmentation fault with latest git (070c57df)

## tl;dr

4 messages between Jan 31, 2013 and Jan 31, 2013.

replies: 3people: 3as markdown or json

Jongman Heo· Jan 31, 2013, 01:35 UTC · lore

Hi all,

Looks like following commit causes a segmentation fault in my machine (when running git pull or git fetch);

commit 8dd5afc926acb9829ebf56e9b78826a5242cd638
Author: Junio C Hamano <gitster@pobox.com>
Date:   Mon Jan 7 12:24:55 2013 -0800

    string-list: allow case-insensitive string list

In my case, list->cmp (at get_entry_index() function) has an invalid address, obviously not an address of string comparision function, instead it points to 1.

Regards, Jongman Heo.

Jeff King· Jan 31, 2013, 06:49 UTC · re: Jongman Heo · lore

Re: Segmentation fault with latest git (070c57df)

On Thu, Jan 31, 2013 at 01:35:21AM +0000, Jongman Heo wrote:

Show 13 quoted lines

> Looks like following commit causes a segmentation fault in my machine
> (when running git pull or git fetch);
> 
> commit 8dd5afc926acb9829ebf56e9b78826a5242cd638
> Author: Junio C Hamano <gitster@pobox.com>
> Date:   Mon Jan 7 12:24:55 2013 -0800
> 
>     string-list: allow case-insensitive string list
> 
> 
> In my case, list->cmp (at get_entry_index() function) has an invalid
> address, obviously not an address of string comparision function,
> instead it points to 1.

Can you show us a stack trace? The string-list functions are generic and get called in a lot of places. It would be useful to know which list is causing the problem.

-Peff

Antoine Pelisse· Jan 31, 2013, 07:02 UTC · re: Jeff King · lore

Re: Segmentation fault with latest git (070c57df)

In "clean.c" we have a "string_list" created on the stack with "STRING_LIST_INIT_NODUP" (there are probably others, I stopped at the first occurrence). But, "STRING_LIST_INIT_NODUP" doesn't init the "list->cmp" pointer which can thus be random.

I don't have much time to provide a patch right now (have to go to work), but will tonight if still needed.

Antoine,

On Thu, Jan 31, 2013 at 7:49 AM, Jeff King <peff@peff.net> wrote:

Show 25 quoted lines

> On Thu, Jan 31, 2013 at 01:35:21AM +0000, Jongman Heo wrote:
>
>> Looks like following commit causes a segmentation fault in my machine
>> (when running git pull or git fetch);
>>
>> commit 8dd5afc926acb9829ebf56e9b78826a5242cd638
>> Author: Junio C Hamano <gitster@pobox.com>
>> Date:   Mon Jan 7 12:24:55 2013 -0800
>>
>>     string-list: allow case-insensitive string list
>>
>>
>> In my case, list->cmp (at get_entry_index() function) has an invalid
>> address, obviously not an address of string comparision function,
>> instead it points to 1.
>
> Can you show us a stack trace? The string-list functions are generic and
> get called in a lot of places. It would be useful to know which list is
> causing the problem.
>
> -Peff
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Jeff King· Jan 31, 2013, 07:35 UTC · re: Antoine Pelisse · lore

Re: Segmentation fault with latest git (070c57df)

On Thu, Jan 31, 2013 at 08:02:06AM +0100, Antoine Pelisse wrote:

Show 5 quoted lines

> In "clean.c" we have a "string_list" created on the stack with
> "STRING_LIST_INIT_NODUP" (there are probably others, I stopped at the
> first occurrence).
> But, "STRING_LIST_INIT_NODUP" doesn't init the "list->cmp" pointer
> which can thus be random.

I don't think that is the problem. Extra struct members that are not mentioned by an initializer will get set to 0 or NULL.

A code path that tried to initialize each member individually would run into problems, but I could not find any such code path (all of them either use an initializer, are static, or memset the struct to all-zeroes).

-Peff