Atm until the DPCD for a connector is read the max link rate and lane
count params are invalid. If the connector is modeset, in
intel_dp_compute_config(), intel_dp_common_len_rate_limit(max_link_rate)
will return 0, leading to a intel_dp->common_rates[-1] access.
Fix the above by making sure the max link params are always valid.
The above access leads to an undefined behaviour by definition, though
not causing a user visible problem to my best knowledge, see the previous
patch why. Nevertheless it is an undefined behaviour and it triggers a
BUG() in CONFIG_UBSAN builds, hence CC:stable.
Cc: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Imre Deak <imre.deak(a)intel.com>
---
drivers/gpu/drm/i915/display/intel_dp.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 153ae944a354b..1935eb49f9574 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1864,6 +1864,12 @@ void intel_dp_set_link_params(struct intel_dp *intel_dp,
intel_dp->lane_count = lane_count;
}
+static void intel_dp_reset_max_link_params(struct intel_dp *intel_dp)
+{
+ intel_dp->max_link_lane_count = intel_dp_max_common_lane_count(intel_dp);
+ intel_dp->max_link_rate = intel_dp_max_common_rate(intel_dp);
+}
+
/* Enable backlight PWM and backlight PP control. */
void intel_edp_backlight_on(const struct intel_crtc_state *crtc_state,
const struct drm_connector_state *conn_state)
@@ -2023,8 +2029,7 @@ void intel_dp_sync_state(struct intel_encoder *encoder,
if (intel_dp->dpcd[DP_DPCD_REV] == 0)
intel_dp_get_dpcd(intel_dp);
- intel_dp->max_link_lane_count = intel_dp_max_common_lane_count(intel_dp);
- intel_dp->max_link_rate = intel_dp_max_common_rate(intel_dp);
+ intel_dp_reset_max_link_params(intel_dp);
}
bool intel_dp_initial_fastset_check(struct intel_encoder *encoder,
@@ -2597,6 +2602,7 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
intel_dp_set_sink_rates(intel_dp);
intel_dp_set_common_rates(intel_dp);
+ intel_dp_reset_max_link_params(intel_dp);
/* Read the eDP DSC DPCD registers */
if (DISPLAY_VER(dev_priv) >= 10)
@@ -4338,12 +4344,7 @@ intel_dp_detect(struct drm_connector *connector,
* supports link training fallback params.
*/
if (intel_dp->reset_link_params || intel_dp->is_mst) {
- /* Initial max link lane count */
- intel_dp->max_link_lane_count = intel_dp_max_common_lane_count(intel_dp);
-
- /* Initial max link rate */
- intel_dp->max_link_rate = intel_dp_max_common_rate(intel_dp);
-
+ intel_dp_reset_max_link_params(intel_dp);
intel_dp->reset_link_params = false;
}
@@ -5011,6 +5012,7 @@ intel_dp_init_connector(struct intel_digital_port *dig_port,
intel_dp_set_source_rates(intel_dp);
intel_dp_set_default_sink_rates(intel_dp);
intel_dp_set_common_rates(intel_dp);
+ intel_dp_reset_max_link_params(intel_dp);
if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
intel_dp->pps.active_pipe = vlv_active_pipe(intel_dp);
--
2.27.0
Reading out the DP encoders' DPCD during booting or resume is only
required for enabled encoders: such encoders may be modesetted during
the initial commit and the link training this involves depends on an
initialized DPCD. For DDI encoders reading out the DPCD is skipped, do
the same on pre-DDI platforms.
Atm, the first DPCD readout without a sink connected - which is a likely
scneario if the encoder is disabled - leaves intel_dp->num_common_rates
at 0, which resulted in
intel_dp_sync_state()->intel_dp_max_common_rate()
in a
intel_dp->common_rates[-1]
access. This by definition results in an undefined behaviour, though to
my best knowledge in all HW/compiler configurations it actually results
in accessing the array item type value preceding the array. In this
case the preceding value happens to be intel_dp->num_common_rates,
which is 0, so this issue - by luck - didn't cause a user visible
problem.
Nevertheless it's still an undefined behaviour and in CONFIG_UBSAN
builds leads to a kernel BUG() (which revealed this problem for us),
hence CC:stable.
A related problem in case the encoder is enabled but the sink is not
connected or the DPCD readout fails is fixed by the next patch.
v2: Amend the commit message describing the root cause of the
CONFIG_UBSAN BUG().
Fixes: a532cde31de3 ("drm/i915/tc: Fix TypeC port init/resume time sanitization")
References: https://gitlab.freedesktop.org/drm/intel/-/issues/4297
Reported-and-tested-by: Mat Jonczyk <mat.jonczyk(a)o2.pl>
Cc: Mat Jonczyk <mat.jonczyk(a)o2.pl>
Cc: José Roberto de Souza <jose.souza(a)intel.com>
Cc: Jani Nikula <jani.nikula(a)intel.com>
Cc: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Imre Deak <imre.deak(a)intel.com>
---
drivers/gpu/drm/i915/display/intel_dp.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 9d8132dd4cc5a..23de500d56b52 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2007,6 +2007,9 @@ void intel_dp_sync_state(struct intel_encoder *encoder,
{
struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+ if (!crtc_state)
+ return;
+
/*
* Don't clobber DPCD if it's been already read out during output
* setup (eDP) or detect.
--
2.27.0
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7ff4034e910fe00a90d985f0d05bacf60c162f02 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd(a)arndb.de>
Date: Mon, 27 Sep 2021 13:36:56 +0200
Subject: [PATCH] staging: vc04_services: shut up out-of-range warning
The comparison against SIZE_MAX produces a harmless warning on 64-bit
architectures:
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:185:16: error: result of comparison of constant 419244183493398898 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Shut up that warning by adding a cast to a longer type.
Fixes: ca641bae6da9 ("staging: vc04_services: prevent integer overflow in create_pagelist()")
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Link: https://lore.kernel.org/r/20210927113702.3866843-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index b25369a13452..967f10b9582a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -182,7 +182,7 @@ create_pagelist(char *buf, char __user *ubuf,
offset = (uintptr_t)ubuf & (PAGE_SIZE - 1);
num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
- if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
+ if ((size_t)num_pages > (SIZE_MAX - sizeof(struct pagelist) -
sizeof(struct vchiq_pagelist_info)) /
(sizeof(u32) + sizeof(pages[0]) +
sizeof(struct scatterlist)))
The patch below does not apply to the 5.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7ff4034e910fe00a90d985f0d05bacf60c162f02 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd(a)arndb.de>
Date: Mon, 27 Sep 2021 13:36:56 +0200
Subject: [PATCH] staging: vc04_services: shut up out-of-range warning
The comparison against SIZE_MAX produces a harmless warning on 64-bit
architectures:
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:185:16: error: result of comparison of constant 419244183493398898 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Shut up that warning by adding a cast to a longer type.
Fixes: ca641bae6da9 ("staging: vc04_services: prevent integer overflow in create_pagelist()")
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Link: https://lore.kernel.org/r/20210927113702.3866843-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index b25369a13452..967f10b9582a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -182,7 +182,7 @@ create_pagelist(char *buf, char __user *ubuf,
offset = (uintptr_t)ubuf & (PAGE_SIZE - 1);
num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
- if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
+ if ((size_t)num_pages > (SIZE_MAX - sizeof(struct pagelist) -
sizeof(struct vchiq_pagelist_info)) /
(sizeof(u32) + sizeof(pages[0]) +
sizeof(struct scatterlist)))
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7ff4034e910fe00a90d985f0d05bacf60c162f02 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd(a)arndb.de>
Date: Mon, 27 Sep 2021 13:36:56 +0200
Subject: [PATCH] staging: vc04_services: shut up out-of-range warning
The comparison against SIZE_MAX produces a harmless warning on 64-bit
architectures:
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:185:16: error: result of comparison of constant 419244183493398898 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Shut up that warning by adding a cast to a longer type.
Fixes: ca641bae6da9 ("staging: vc04_services: prevent integer overflow in create_pagelist()")
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Link: https://lore.kernel.org/r/20210927113702.3866843-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index b25369a13452..967f10b9582a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -182,7 +182,7 @@ create_pagelist(char *buf, char __user *ubuf,
offset = (uintptr_t)ubuf & (PAGE_SIZE - 1);
num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
- if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
+ if ((size_t)num_pages > (SIZE_MAX - sizeof(struct pagelist) -
sizeof(struct vchiq_pagelist_info)) /
(sizeof(u32) + sizeof(pages[0]) +
sizeof(struct scatterlist)))
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7ff4034e910fe00a90d985f0d05bacf60c162f02 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd(a)arndb.de>
Date: Mon, 27 Sep 2021 13:36:56 +0200
Subject: [PATCH] staging: vc04_services: shut up out-of-range warning
The comparison against SIZE_MAX produces a harmless warning on 64-bit
architectures:
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:185:16: error: result of comparison of constant 419244183493398898 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Shut up that warning by adding a cast to a longer type.
Fixes: ca641bae6da9 ("staging: vc04_services: prevent integer overflow in create_pagelist()")
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Link: https://lore.kernel.org/r/20210927113702.3866843-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index b25369a13452..967f10b9582a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -182,7 +182,7 @@ create_pagelist(char *buf, char __user *ubuf,
offset = (uintptr_t)ubuf & (PAGE_SIZE - 1);
num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
- if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
+ if ((size_t)num_pages > (SIZE_MAX - sizeof(struct pagelist) -
sizeof(struct vchiq_pagelist_info)) /
(sizeof(u32) + sizeof(pages[0]) +
sizeof(struct scatterlist)))
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7ff4034e910fe00a90d985f0d05bacf60c162f02 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd(a)arndb.de>
Date: Mon, 27 Sep 2021 13:36:56 +0200
Subject: [PATCH] staging: vc04_services: shut up out-of-range warning
The comparison against SIZE_MAX produces a harmless warning on 64-bit
architectures:
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:185:16: error: result of comparison of constant 419244183493398898 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Shut up that warning by adding a cast to a longer type.
Fixes: ca641bae6da9 ("staging: vc04_services: prevent integer overflow in create_pagelist()")
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Link: https://lore.kernel.org/r/20210927113702.3866843-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index b25369a13452..967f10b9582a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -182,7 +182,7 @@ create_pagelist(char *buf, char __user *ubuf,
offset = (uintptr_t)ubuf & (PAGE_SIZE - 1);
num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
- if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
+ if ((size_t)num_pages > (SIZE_MAX - sizeof(struct pagelist) -
sizeof(struct vchiq_pagelist_info)) /
(sizeof(u32) + sizeof(pages[0]) +
sizeof(struct scatterlist)))
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7ff4034e910fe00a90d985f0d05bacf60c162f02 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd(a)arndb.de>
Date: Mon, 27 Sep 2021 13:36:56 +0200
Subject: [PATCH] staging: vc04_services: shut up out-of-range warning
The comparison against SIZE_MAX produces a harmless warning on 64-bit
architectures:
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:185:16: error: result of comparison of constant 419244183493398898 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Shut up that warning by adding a cast to a longer type.
Fixes: ca641bae6da9 ("staging: vc04_services: prevent integer overflow in create_pagelist()")
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Link: https://lore.kernel.org/r/20210927113702.3866843-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index b25369a13452..967f10b9582a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -182,7 +182,7 @@ create_pagelist(char *buf, char __user *ubuf,
offset = (uintptr_t)ubuf & (PAGE_SIZE - 1);
num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
- if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
+ if ((size_t)num_pages > (SIZE_MAX - sizeof(struct pagelist) -
sizeof(struct vchiq_pagelist_info)) /
(sizeof(u32) + sizeof(pages[0]) +
sizeof(struct scatterlist)))