Re: [Patch 3/9] fs/compat.c: fix resource leaks and wrong goto's

WANG Cong
2008-05-12T03:48:19Z

On Sat, May 10, 2008 at 09:35:43PM +0100, Al Viro wrote:
>On Sat, May 10, 2008 at 08:21:11PM +0100, Al Viro wrote:
>> On Thu, May 08, 2008 at 09:52:28PM +0800, WANG Cong wrote:
>> > Use free_arg_pages() to free the pages allocated by copy_strings_kernel()
>> > on failure. And fix some related wrong goto pathes.
>>
>> Kinda; free_arg_pages() is needed here, but there's no need to mess with
>> goto - just put it under out:
>>
>> Note that it's essentially just a part of freeing bprm; it's _not_ a "clean
>> collected strings, so that we could add new ones".
>
>FWIW, I'd suggest this:

Hmm, looks fine. But, see below.

>
>diff --git a/fs/compat.c b/fs/compat.c
>index 332a869..ed43e17 100644
>--- a/fs/compat.c
>+++ b/fs/compat.c
>@@ -1405,7 +1405,7 @@ int compat_do_execve(char * filename,
> /* execve success */
> security_bprm_free(bprm);
> acct_update_integrals(current);
>- kfree(bprm);
>+ free_bprm(bprm);
> return retval;
> }
>
>@@ -1424,7 +1424,7 @@ out_file:
> }
>
> out_kfree:
>- kfree(bprm);
>+ free_bprm(bprm);
>
> out_ret:
> return retval;
>diff --git a/fs/exec.c b/fs/exec.c
>index aeaa979..ad545b0 100644
>--- a/fs/exec.c
>+++ b/fs/exec.c
>@@ -1251,6 +1251,12 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
>
> EXPORT_SYMBOL(search_binary_handler);
>
>+void free_bprm(struct linux_binprm *bprm)
>+{
>+ free_arg_pages(bprm);
>+ kfree(bprm);
>+}
>+
> /*
> * sys_execve() executes a new program.
> */
>@@ -1320,17 +1326,15 @@ int do_execve(char * filename,
> retval = search_binary_handler(bprm,regs);
> if (retval >= 0) {
> /* execve success */
>- free_arg_pages(bprm);
> security_bprm_free(bprm);
> acct_update_integrals(current);
>- kfree(bprm);
>+ free_bprm(bprm);
> if (displaced)
> put_files_struct(displaced);
> return retval;
> }
>
> out:
>- free_arg_pages(bprm);

Why just drop this? No need to call free_bprm()?

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