Messages in this thread | | | From | Kees Cook <> | Date | Mon, 30 Oct 2017 17:14:59 -0700 | Subject | Re: [lkp-robot] [printk] 7f7c60e066: BUG:KASAN:slab-out-of-bounds |
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On Wed, Oct 25, 2017 at 9:22 AM, kernel test robot <xiaolong.ye@intel.com> wrote: > > FYI, we noticed the following commit (built with gcc-4.9): > > commit: 7f7c60e0663645e757e520245606fde9c6e326bb ("printk: hash addresses printed with %p") > url: https://github.com/0day-ci/linux/commits/Tobin-C-Harding/printk-hash-addresses-printed-with-p/20171024-231922
It's not clear to me which of the various versions this test ran against, but it seems like the printf self-tests got very confused by the results:
> [ 40.275423] test_printf: kvasprintf(..., "%p %p", ...) returned '3cf9adbe eff717bf', expected '0000000001234567 fffffffffedcba98' > [ 40.296739] test_printf: vsnprintf(buf, 256, "|%-*p|%*p|", ...) returned 19, expected 39 > [ 40.322776] test_printf: vsnprintf(buf, 16, "|%-*p|%*p|", ...) returned 19, expected 39 > [ 40.334834] test_printf: vsnprintf(buf, 0, "|%-*p|%*p|", ...) returned 19, expected 39
I assume v10 will fix the width issues, but probably not the value tests...
And it claims a use-after-free, too:
> [ 39.757461] The buggy address belongs to the object at 22cb34bb > [ 39.757461] which belongs to the cache kmalloc-32 of size 32 > [ 39.757461] The buggy address is located 0 bytes inside of > [ 39.757461] 32-byte region [22cb34bb, 24ac3a60)
Which becomes rather unreadable, since the address got hashed. :P
-Kees
-- Kees Cook Pixel Security
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