On 11.05.2021 10:28:28, Torin Cooper-Bennun wrote:
> On Mon, May 10, 2021 at 08:18:07PM +0200, Marc Kleine-Budde wrote:
> > I have a git feeling that I've found the problem. Can you revert
> > e940e0895a82 ("can: skb: can_skb_set_owner(): fix ref counting if socket
> > was closed before setting skb ownership") and check if that fixes your
> > problem? This might trigger the problem described in the patch:
> >
> > | WARNING: CPU: 0 PID: 280 at lib/refcount.c:25 refcount_warn_saturate+0x114/0x134
> > | refcount_t: addition on 0; use-after-free.
> > | Modules linked in: coda_vpu(E) v4l2_jpeg(E) videobuf2_vmalloc(E) imx_vdoa(E)
> > | CPU: 0 PID: 280 Comm: test_can.sh Tainted: G E 5.11.0-04577-gf8ff6603c617 #203
> > | Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> > | Backtrace:
> > | [<80bafea4>] (dump_backtrace) from [<80bb0280>] (show_stack+0x20/0x24) r7:00000000 r6:600f0113 r5:00000000 r4:81441220
> > | [<80bb0260>] (show_stack) from [<80bb593c>] (dump_stack+0xa0/0xc8)
> > | [<80bb589c>] (dump_stack) from [<8012b268>] (__warn+0xd4/0x114) r9:00000019 r8:80f4a8c2 r7:83e4150c r6:00000000 r5:00000009 r4:80528f90
> > | [<8012b194>] (__warn) from [<80bb09c4>] (warn_slowpath_fmt+0x88/0xc8) r9:83f26400 r8:80f4a8d1 r7:00000009 r6:80528f90 r5:00000019 r4:80f4a8c2
> > | [<80bb0940>] (warn_slowpath_fmt) from [<80528f90>] (refcount_warn_saturate+0x114/0x134) r8:00000000 r7:00000000 r6:82b44000 r5:834e5600 r4:83f4d540
> > | [<80528e7c>] (refcount_warn_saturate) from [<8079a4c8>] (__refcount_add.constprop.0+0x4c/0x50)
> > | [<8079a47c>] (__refcount_add.constprop.0) from [<8079a57c>] (can_put_echo_skb+0xb0/0x13c)
> > | [<8079a4cc>] (can_put_echo_skb) from [<8079ba98>] (flexcan_start_xmit+0x1c4/0x230) r9:00000010 r8:83f48610 r7:0fdc0000 r6:0c080000 r5:82b44000 r4:834e5600
> > | [<8079b8d4>] (flexcan_start_xmit) from [<80969078>] (netdev_start_xmit+0x44/0x70) r9:814c0ba0 r8:80c8790c r7:00000000 r6:834e5600 r5:82b44000 r4:82ab1f00
> > | [<80969034>] (netdev_start_xmit) from [<809725a4>] (dev_hard_start_xmit+0x19c/0x318) r9:814c0ba0 r8:00000000 r7:82ab1f00 r6:82b44000 r5:00000000 r4:834e5600
> > | [<80972408>] (dev_hard_start_xmit) from [<809c6584>] (sch_direct_xmit+0xcc/0x264) r10:834e5600 r9:00000000 r8:00000000 r7:82b44000 r6:82ab1f00 r5:834e5600 r4:83f27400
> > | [<809c64b8>] (sch_direct_xmit) from [<809c6c0c>] (__qdisc_run+0x4f0/0x534)
> >
> > Can you give me feedback if
> > 1. the revert "fixes" your problem
> > 2. the revert triggers the above backtrace
>
> Always trust your git, it seems... I can confirm this revert both
> 'fixes' the problem and triggers that backtrace originating from
> m_can_tx_handler.
\o/
> I got two of those backtraces during the run, and
> sandwiched between them a backtrace from the rx path:
>
> | WARNING: CPU: 2 PID: 22 at lib/refcount.c:28 refcount_warn_saturate+0x13c/0x174
> | refcount_t: underflow; use-after-free.
Now please test if
https://lore.kernel.org/linux-can/20210510182038.1528631-1-mkl@xxxxxxxxxxxxxx/
fixes your problem.
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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