Re: [PATCH -next] exec: Fix mem leak in kernel_read_file

[Dmitry Kasatkin <dmitry.kasatkin@huawei.com>]

On 13/03/2019 16:38, gregkh@linuxfoundation.org wrote:
> On Wed, Mar 13, 2019 at 02:12:30PM +0000, Dmitry Kasatkin wrote:
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>> From: Sasha Levin <sashal@kernel.org>
>> Sent: Tuesday, March 12, 2019 1:16 AM
>> To: Dmitry Kasatkin
>> Cc: Al Viro; yuehaibing; linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org; keescook@chromium.org; stable@vger.kernel.org; gregkh@google.com
>> Subject: Re: [PATCH -next] exec: Fix mem leak in kernel_read_file
>>      
>> On Mon, Mar 11, 2019 at 04:59:14PM +0000, Dmitry Kasatkin wrote:
>>>
>>> From: Al Viro <viro@ftp.linux.org.uk> on behalf of Al Viro <viro@zeniv.linux.org.uk>
>>> Sent: Tuesday, February 19, 2019 4:25 AM
>>> To: yuehaibing
>>> Cc: linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org; Dmitry Kasatkin; keescook@chromium.org
>>> Subject: Re: [PATCH -next] exec: Fix mem leak in kernel_read_file
>>>   
>>> On Tue, Feb 19, 2019 at 10:10:38AM +0800, YueHaibing wrote:
>>>> syzkaller report this:
>>>> BUG: memory leak
>>>> unreferenced object 0xffffc9000488d000 (size 9195520):
>>>>     comm "syz-executor.0", pid 2752, jiffies 4294787496 (age 18.757s)
>>>>     hex dump (first 32 bytes):
>>>>       ff ff ff ff ff ff ff ff a8 00 00 00 01 00 00 00  ................
>>>>       02 00 00 00 00 00 00 00 80 a1 7a c1 ff ff ff ff  ..........z.....
>>>>     backtrace:
>>>>       [<000000000863775c>] __vmalloc_node mm/vmalloc.c:1795 [inline]
>>>>       [<000000000863775c>] __vmalloc_node_flags mm/vmalloc.c:1809 [inline]
>>>>       [<000000000863775c>] vmalloc+0x8c/0xb0 mm/vmalloc.c:1831
>>>>       [<000000003f668111>] kernel_read_file+0x58f/0x7d0 fs/exec.c:924
>>>>       [<000000002385813f>] kernel_read_file_from_fd+0x49/0x80 fs/exec.c:993
>>>>       [<0000000011953ff1>] __do_sys_finit_module+0x13b/0x2a0 kernel/module.c:3895
>>>>       [<000000006f58491f>] do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
>>>>       [<00000000ee78baf4>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
>>>>       [<00000000241f889b>] 0xffffffffffffffff
>>>>
>>>> It should goto 'out_free' lable to free allocated buf while kernel_read
>>>> fails.
>>>
>>> Applied.
>>>
>>>
>>> This must be applied to stables as well...
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>>> It's already in all relevant stable trees...
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>> I only can see in longterm 4.19.
>>
>> What about 4.9 and 4.14?
> 
> It was in the queue already for that (you can see it on git.kernel.org),
> and they are now part of the -rc releases that are currently out for
> review.
> 
> thanks,
> 
> greg k-h
> 

Thanks!

Dmitry