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

[Dmitry Kasatkin]

On 13/03/2019 16:38, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
> On Wed, Mar 13, 2019 at 02:12:30PM +0000, Dmitry Kasatkin wrote:
> > From: Sasha Levin <sashal@xxxxxxxxxx>
> > Sent: Tuesday, March 12, 2019 1:16 AM
> > To: Dmitry Kasatkin
> > Cc: Al Viro; yuehaibing; linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; keescook@xxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx; gregkh@xxxxxxxxxx
> > 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@xxxxxxxxxxxxxxxx> on behalf of Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> > > Sent: Tuesday, February 19, 2019 4:25 AM
> > > To: yuehaibing
> > > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; Dmitry Kasatkin; keescook@xxxxxxxxxxxx
> > > 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):
> > > >  ÂÂ comm "syz-executor.0", pid 2752, jiffies 4294787496 (age 18.757s)
> > > >  ÂÂ hex dump (first 32 bytes):
> > > >  ÂÂÂÂ ff ff ff ff ff ff ff ff a8 00 00 00 01 00 00 00Â ................
> > > >   02 00 00 00 00 00 00 00 80 a1 7a c1 ff ff ff ff ..........z.....
> > > >  ÂÂ backtrace:
> > > >  ÂÂÂÂ [<000000000863775c>] __vmalloc_node mm/vmalloc.c:1795 [inline]
> > > >  ÂÂÂÂ [<000000000863775c>] __vmalloc_node_flags mm/vmalloc.c:1809 [inline]
> > > >  ÂÂÂÂ [<000000000863775c>] vmalloc+0x8c/0xb0 mm/vmalloc.c:1831
> > > >  ÂÂÂÂ [<000000003f668111>] kernel_read_file+0x58f/0x7d0 fs/exec.c:924
> > > >  ÂÂÂÂ [<000000002385813f>] kernel_read_file_from_fd+0x49/0x80 fs/exec.c:993
> > > >  ÂÂÂÂ [<0000000011953ff1>] __do_sys_finit_module+0x13b/0x2a0 kernel/module.c:3895
> > > >  ÂÂÂÂ [<000000006f58491f>] do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
> > > >  ÂÂÂÂ [<00000000ee78baf4>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > > >  ÂÂÂÂ [<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...
> >
> > > It's already in all relevant stable trees...
> >
> > 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