Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1538889

Re: [RFC 02/10] module: fix memory leak on early load_module() failures

Show all headers | View raw

On Thu, Dec 8, 2016 at 1:10 PM, Luis R. Rodriguez <mcgrof@kernel.org> wrote:
> On Thu, Dec 8, 2016 at 2:30 PM, Kees Cook <keescook@chromium.org> wrote:
>> On Thu, Dec 8, 2016 at 11:48 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote:
>>> While looking for early possible module loading failures I was
>>> able to reproduce a memory leak possible with kmemleak. There
>>> are a few rare ways to trigger a failure:
>>>
>>>   o we've run into a failure while processing kernel parameters
>>>     (parse_args() returns an error)
>>>   o mod_sysfs_setup() fails
>>>   o we're a live patch module and copy_module_elf() fails
>>>
>>> Chances of running into this issue is really low.
>>>
>>> kmemleak splat:
>>>
>>> unreferenced object 0xffff9f2c4ada1b00 (size 32):
>>>   comm "kworker/u16:4", pid 82, jiffies 4294897636 (age 681.816s)
>>>   hex dump (first 32 bytes):
>>>     6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00  memstick0.......
>>>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>>>   backtrace:
>>>     [<ffffffff8c6cfeba>] kmemleak_alloc+0x4a/0xa0
>>>     [<ffffffff8c200046>] __kmalloc_track_caller+0x126/0x230
>>>     [<ffffffff8c1bc581>] kstrdup+0x31/0x60
>>>     [<ffffffff8c1bc5d4>] kstrdup_const+0x24/0x30
>>>     [<ffffffff8c3c23aa>] kvasprintf_const+0x7a/0x90
>>>     [<ffffffff8c3b5481>] kobject_set_name_vargs+0x21/0x90
>>>     [<ffffffff8c4fbdd7>] dev_set_name+0x47/0x50
>>>     [<ffffffffc07819e5>] memstick_check+0x95/0x33c [memstick]
>>>     [<ffffffff8c09c893>] process_one_work+0x1f3/0x4b0
>>>     [<ffffffff8c09cb98>] worker_thread+0x48/0x4e0
>>>     [<ffffffff8c0a2b79>] kthread+0xc9/0xe0
>>>     [<ffffffff8c6dab5f>] ret_from_fork+0x1f/0x40
>>>     [<ffffffffffffffff>] 0xffffffffffffffff
>>>
>>> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
>>
>> Acked-by: Kees Cook <keescook@chromium.org>
>>
>> Is this worth sending through -stable too?
>
> Yes, for some reason git-send e-mail complained to me about
> stable@kernel.org not being a valid local address, so I had to remove
> it, but indeed. I'll try to fix this e-mail issue later and add your
> tag.

Yup, you want stable@vger.kernel.org. :)

-Kees

-- 
Kees Cook
Nexus Security

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RFC 00/10] kmod: stress test driver, few fixes and enhancements "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 19:50 +0100
  [RFC 02/10] module: fix memory leak on early load_module() failures "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100
    Re: [RFC 02/10] module: fix memory leak on early load_module() failures Kees Cook <keescook@chromium.org> - 2016-12-08 21:40 +0100
      Re: [RFC 02/10] module: fix memory leak on early load_module() failures "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 22:20 +0100
        Re: [RFC 02/10] module: fix memory leak on early load_module() failures Kees Cook <keescook@chromium.org> - 2016-12-08 22:20 +0100
    Re: [RFC 02/10] module: fix memory leak on early load_module()  failures Miroslav Benes <mbenes@suse.cz> - 2016-12-09 18:10 +0100
  [RFC 08/10] sysctl: add support for unsigned int properly "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100
  [RFC 05/10] kmod: return -EBUSY if modprobe limit is reached "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100
  [RFC 07/10] kmod: use simplified rate limit printk "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100
  [RFC 04/10] kmod: provide wrappers for kmod_concurrent inc/dec "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100
    Re: [RFC 04/10] kmod: provide wrappers for kmod_concurrent inc/dec Kees Cook <keescook@chromium.org> - 2016-12-08 21:40 +0100
      Re: [RFC 04/10] kmod: provide wrappers for kmod_concurrent inc/dec "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 22:10 +0100
  [RFC 06/10] kmod: provide sanity check on kmod_concurrent access "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100
  [RFC 10/10] kmod: add a sanity check on module loading "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100
    Re: [RFC 10/10] kmod: add a sanity check on module loading Martin Wilck <mwilck@suse.com> - 2016-12-09 21:10 +0100
      Re: [RFC 10/10] kmod: add a sanity check on module loading Linus Torvalds <torvalds@linux-foundation.org> - 2016-12-09 22:00 +0100
  [RFC 03/10] kmod: add dynamic max concurrent thread count "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100
    Re: [RFC 03/10] kmod: add dynamic max concurrent thread count Kees Cook <keescook@chromium.org> - 2016-12-08 21:30 +0100
      Re: [RFC 03/10] kmod: add dynamic max concurrent thread count "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 22:10 +0100
  [RFC 09/10] kmod: add helpers for getting kmod count and limit "Luis R. Rodriguez" <mcgrof@kernel.org> - 2016-12-08 20:50 +0100

csiph-web