linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Will Deacon <will.deacon@arm.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
	Arnd Bergmann <arnd@arndb.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Richard Henderson <rth@twiddle.net>,
	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	Matt Turner <mattst88@gmail.com>,
	Russell King <linux@armlinux.org.uk>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Tony Luck <tony.luck@intel.com>,
	Fenghua Yu <fenghua.yu@intel.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Michal Simek <monstr@monstr.eu>,
	Ralf Baechle <ralf@linux-mips.org>,
	Paul Burton <paul.burton@mips.com>,
	James Hogan <jhogan@kernel.org>,
	"James E . J . Bottomley" <James.Bottomley@HansenPartnership.com>,
	Helge Deller <deller@gmx.de>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Rich Felker <dalias@libc.org>,
	"David S . Miller" <davem@davemloft.net>,
	Max Filippov <jcmvbkbc@gmail.com>,
	Firoz Khan <firoz.khan@linaro.org>,
	linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org,
	linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org,
	linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
	sparclinux@vger.kernel.org
Subject: Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
Date: Wed, 3 Apr 2019 16:19:32 +0100	[thread overview]
Message-ID: <20190403151932.GA16866@fuggles.cambridge.arm.com> (raw)
In-Reply-To: <9d673dfd-0051-3676-653e-6376430d73dd@kernel.dk>

Hi Jens,

On Wed, Apr 03, 2019 at 07:49:26AM -0600, Jens Axboe wrote:
> On 4/3/19 5:11 AM, Will Deacon wrote:
> > will@autoplooker:~/liburing/test$ ./io_uring_register 
> > RELIMIT_MEMLOCK: 67108864 (67108864)
> > [   35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
> > [   35.478969] Mem abort info:
> > [   35.479296]   ESR = 0x96000004
> > [   35.479785]   Exception class = DABT (current EL), IL = 32 bits
> > [   35.480528]   SET = 0, FnV = 0
> > [   35.480980]   EA = 0, S1PTW = 0
> > [   35.481345] Data abort info:
> > [   35.481680]   ISV = 0, ISS = 0x00000004
> > [   35.482267]   CM = 0, WnR = 0
> > [   35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
> > [   35.483486] [0000000000000070] pgd=0000000000000000
> > [   35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> > [   35.484788] Modules linked in:
> > [   35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1
> > [   35.486712] Hardware name: linux,dummy-virt (DT)
> > [   35.487450] pstate: 20400005 (nzCv daif +PAN -UAO)
> > [   35.488228] pc : link_pwq+0x10/0x60
> > [   35.488794] lr : apply_wqattrs_commit+0xe0/0x118
> > [   35.489550] sp : ffff000017e2bbc0
> 
> Huh, this looks odd, it's crashing inside the wq setup.

Enabling KASAN seems to indicate a double-free, which may well be related.

Will

[  149.890370] ==================================================================
[  149.891266] BUG: KASAN: double-free or invalid-free in io_sqe_files_unregister+0xa8/0x140
[  149.892218] 
[  149.892411] CPU: 113 PID: 3974 Comm: io_uring_regist Tainted: G    B             5.1.0-rc3-00012-g40b114779944 #3
[  149.893623] Hardware name: linux,dummy-virt (DT)
[  149.894169] Call trace:
[  149.894539]  dump_backtrace+0x0/0x228
[  149.895172]  show_stack+0x14/0x20
[  149.895747]  dump_stack+0xe8/0x124
[  149.896335]  print_address_description+0x60/0x258
[  149.897148]  kasan_report_invalid_free+0x78/0xb8
[  149.897936]  __kasan_slab_free+0x1fc/0x228
[  149.898641]  kasan_slab_free+0x10/0x18
[  149.899283]  kfree+0x70/0x1f8
[  149.899798]  io_sqe_files_unregister+0xa8/0x140
[  149.900574]  io_ring_ctx_wait_and_kill+0x190/0x3c0
[  149.901402]  io_uring_release+0x2c/0x48
[  149.902068]  __fput+0x18c/0x510
[  149.902612]  ____fput+0xc/0x18
[  149.903146]  task_work_run+0xf0/0x148
[  149.903778]  do_notify_resume+0x554/0x748
[  149.904467]  work_pending+0x8/0x10
[  149.905060] 
[  149.905331] Allocated by task 3974:
[  149.905934]  __kasan_kmalloc.isra.0.part.1+0x48/0xf8
[  149.906786]  __kasan_kmalloc.isra.0+0xb8/0xd8
[  149.907531]  kasan_kmalloc+0xc/0x18
[  149.908134]  __kmalloc+0x168/0x248
[  149.908724]  __arm64_sys_io_uring_register+0x2b8/0x15a8
[  149.909622]  el0_svc_common+0x100/0x258
[  149.910281]  el0_svc_handler+0x48/0xc0
[  149.910928]  el0_svc+0x8/0xc
[  149.911425] 
[  149.911696] Freed by task 3974:
[  149.912242]  __kasan_slab_free+0x114/0x228
[  149.912955]  kasan_slab_free+0x10/0x18
[  149.913602]  kfree+0x70/0x1f8
[  149.914118]  __arm64_sys_io_uring_register+0xc2c/0x15a8
[  149.915009]  el0_svc_common+0x100/0x258
[  149.915670]  el0_svc_handler+0x48/0xc0
[  149.916317]  el0_svc+0x8/0xc
[  149.916817] 
[  149.917101] The buggy address belongs to the object at ffff8004ce07ed00
[  149.917101]  which belongs to the cache kmalloc-128 of size 128
[  149.919197] The buggy address is located 0 bytes inside of
[  149.919197]  128-byte region [ffff8004ce07ed00, ffff8004ce07ed80)
[  149.921142] The buggy address belongs to the page:
[  149.921953] page:ffff7e0013381f00 count:1 mapcount:0 mapping:ffff800503417c00 index:0x0 compound_mapcount: 0
[  149.923595] flags: 0x1ffff00000010200(slab|head)
[  149.924388] raw: 1ffff00000010200 dead000000000100 dead000000000200 ffff800503417c00
[  149.925706] raw: 0000000000000000 0000000080400040 00000001ffffffff 0000000000000000
[  149.927011] page dumped because: kasan: bad access detected
[  149.927956] 
[  149.928224] Memory state around the buggy address:
[  149.929054]  ffff8004ce07ec00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
[  149.930274]  ffff8004ce07ec80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  149.931494] >ffff8004ce07ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  149.932712]                    ^
[  149.933281]  ffff8004ce07ed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  149.934508]  ffff8004ce07ee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  149.935725] ==================================================================

  reply	other threads:[~2019-04-03 15:19 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-25 14:34 [PATCH 1/2] io_uring: fix big-endian compat signal mask handling Arnd Bergmann
2019-03-25 14:47 ` [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere Arnd Bergmann
2019-03-25 17:37   ` Paul Burton
2019-03-26  8:40     ` Arnd Bergmann
2019-03-30  9:42   ` Heiko Carstens
2019-03-31  9:47   ` Michael Ellerman
2019-03-31 16:28     ` Arnd Bergmann
2019-04-03  1:19       ` Michael Ellerman
2019-04-01  8:19   ` Geert Uytterhoeven
2019-04-03  2:47   ` Michael Ellerman
2019-04-03 11:11     ` Will Deacon
2019-04-03 13:49       ` Jens Axboe
2019-04-03 15:19         ` Will Deacon [this message]
2019-04-03 15:39           ` Jens Axboe
2019-04-03 15:49             ` Will Deacon
2019-04-03 15:51               ` Jens Axboe
2019-04-04  6:08         ` Michael Ellerman
2019-03-25 16:05 ` [PATCH 1/2] io_uring: fix big-endian compat signal mask handling Jens Axboe
2019-03-25 16:11   ` Arnd Bergmann
2019-03-25 16:15     ` Jens Axboe
2019-03-25 16:19 ` James Bottomley
2019-03-25 16:23   ` Jens Axboe
2019-03-25 16:24   ` Arnd Bergmann
2019-03-26  0:13     ` James Bottomley
2019-03-26  8:35       ` Arnd Bergmann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190403151932.GA16866@fuggles.cambridge.arm.com \
    --to=will.deacon@arm.com \
    --cc=James.Bottomley@HansenPartnership.com \
    --cc=akpm@linux-foundation.org \
    --cc=arnd@arndb.de \
    --cc=axboe@kernel.dk \
    --cc=benh@kernel.crashing.org \
    --cc=catalin.marinas@arm.com \
    --cc=dalias@libc.org \
    --cc=davem@davemloft.net \
    --cc=deller@gmx.de \
    --cc=fenghua.yu@intel.com \
    --cc=firoz.khan@linaro.org \
    --cc=geert@linux-m68k.org \
    --cc=heiko.carstens@de.ibm.com \
    --cc=ink@jurassic.park.msu.ru \
    --cc=jcmvbkbc@gmail.com \
    --cc=jhogan@kernel.org \
    --cc=linux-alpha@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-ia64@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-m68k@lists.linux-m68k.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=linux-parisc@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mattst88@gmail.com \
    --cc=monstr@monstr.eu \
    --cc=mpe@ellerman.id.au \
    --cc=paul.burton@mips.com \
    --cc=paulus@samba.org \
    --cc=ralf@linux-mips.org \
    --cc=rth@twiddle.net \
    --cc=schwidefsky@de.ibm.com \
    --cc=sparclinux@vger.kernel.org \
    --cc=tony.luck@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).