[PATCH] drm/i915/gvt: Fix the validation on size field of dp aux header
Du, Changbin
changbin.du at intel.com
Wed Apr 11 08:11:15 UTC 2018
On Wed, Apr 11, 2018 at 02:22:01PM +0800, Zhenyu Wang wrote:
>
> Fixes line pls.
>
This is pretty old code (maybe from initial state), still need Fixes tag?
Sometimes it is not easy to find original change which introduced misstakes.
> On 2018.04.10 13:02:30 +0800, changbin.du at intel.com wrote:
> > From: Changbin Du <changbin.du at intel.com>
> >
> > The assertion for len is wrong, so fix it. And for where to validate
> > user input, we should not warn by call trace.
> >
> > [ 290.584739] WARNING: CPU: 0 PID: 1471 at drivers/gpu/drm/i915/gvt/handlers.c:969 dp_aux_ch_ctl_mmio_write+0x394/0x430 [i915]
> > [ 290.586113] task: ffff880111fe8000 task.stack: ffffc90044a9c000
> > [ 290.586192] RIP: e030:dp_aux_ch_ctl_mmio_write+0x394/0x430 [i915]
> > [ 290.586258] RSP: e02b:ffffc90044a9fd88 EFLAGS: 00010282
> > [ 290.586315] RAX: 0000000000000017 RBX: 0000000000000003 RCX: ffffffff82461148
> > [ 290.586391] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000201
> > [ 290.586468] RBP: ffffc90043ed1000 R08: 0000000000000248 R09: 00000000000003d8
> > [ 290.586544] R10: ffffc90044bdd314 R11: 0000000000000011 R12: 0000000000064310
> > [ 290.586621] R13: 00000000fe4003ff R14: ffffc900432d1008 R15: ffff88010fa7cb40
> > [ 290.586701] FS: 0000000000000000(0000) GS:ffff880123200000(0000) knlGS:0000000000000000
> > [ 290.586787] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 290.586849] CR2: 00007f67ea44e000 CR3: 0000000116078000 CR4: 0000000000042660
> > [ 290.586926] Call Trace:
> > [ 290.586958] ? __switch_to_asm+0x40/0x70
> > [ 290.587017] intel_vgpu_mmio_reg_rw+0x1ec/0x3c0 [i915]
> > [ 290.587087] intel_vgpu_emulate_mmio_write+0xa8/0x2c0 [i915]
> > [ 290.587151] xengt_emulation_thread+0x501/0x7a0 [xengt]
> > [ 290.587208] ? __schedule+0x3c6/0x890
> > [ 290.587250] ? wait_woken+0x80/0x80
> > [ 290.587290] kthread+0xfc/0x130
> > [ 290.587326] ? xengt_gpa_to_va+0x1f0/0x1f0 [xengt]
> > [ 290.587378] ? kthread_create_on_node+0x70/0x70
> > [ 290.587429] ? do_group_exit+0x3a/0xa0
> > [ 290.587471] ret_from_fork+0x35/0x40
> >
> > Signed-off-by: Changbin Du <changbin.du at intel.com>
> > ---
> > drivers/gpu/drm/i915/gvt/display.h | 2 +-
> > drivers/gpu/drm/i915/gvt/handlers.c | 13 +++++++++----
> > 2 files changed, 10 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gvt/display.h b/drivers/gpu/drm/i915/gvt/display.h
> > index b46b868..ea7c1c5 100644
> > --- a/drivers/gpu/drm/i915/gvt/display.h
> > +++ b/drivers/gpu/drm/i915/gvt/display.h
> > @@ -67,7 +67,7 @@
> > #define AUX_NATIVE_REPLY_NAK (0x1 << 4)
> > #define AUX_NATIVE_REPLY_DEFER (0x2 << 4)
> >
> > -#define AUX_BURST_SIZE 16
> > +#define AUX_BURST_SIZE 20
> >
> > /* DPCD addresses */
> > #define DPCD_REV 0x000
> > diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
> > index a33c1c3e..b77adcc 100644
> > --- a/drivers/gpu/drm/i915/gvt/handlers.c
> > +++ b/drivers/gpu/drm/i915/gvt/handlers.c
> > @@ -900,11 +900,14 @@ static int dp_aux_ch_ctl_mmio_write(struct intel_vgpu *vgpu,
> > }
> >
> > /*
> > - * Write request format: (command + address) occupies
> > - * 3 bytes, followed by (len + 1) bytes of data.
> > + * Write request format: Headr (command + address + size) occupies
> > + * 4 bytes, followed by (len + 1) bytes of data. See details at
> > + * intel_dp_aux_transfer().
> > */
> > - if (WARN_ON((len + 4) > AUX_BURST_SIZE))
> > + if ((len + 1 + 4) > AUX_BURST_SIZE) {
> > + gvt_vgpu_err("dp_aux_header: len %d is too large\n", len);
> > return -EINVAL;
> > + }
> >
> > /* unpack data from vreg to buf */
> > for (t = 0; t < 4; t++) {
> > @@ -968,8 +971,10 @@ static int dp_aux_ch_ctl_mmio_write(struct intel_vgpu *vgpu,
> > /*
> > * Read reply format: ACK (1 byte) plus (len + 1) bytes of data.
> > */
> > - if (WARN_ON((len + 2) > AUX_BURST_SIZE))
> > + if ((len + 2) > AUX_BURST_SIZE) {
> > + gvt_vgpu_err("dp_aux_header: len %d is too large\n", len);
> > return -EINVAL;
> > + }
> >
> > /* read from virtual DPCD to vreg */
> > /* first 4 bytes: [ACK][addr][addr+1][addr+2] */
> > --
> > 2.7.4
> >
> > _______________________________________________
> > intel-gvt-dev mailing list
> > intel-gvt-dev at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
>
> --
> Open Source Technology Center, Intel ltd.
>
> $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
--
Thanks,
Changbin Du
More information about the intel-gvt-dev
mailing list