[ Upstream commit b46064a18810bad3aea089a79993ca5ea7a3d2b2 ]
It turns out that deferred default domain creation leaves a subtle
race window during iommu_device_register() wherein a client driver may
asynchronously probe in parallel and get as far as performing DMA API
operations with dma-direct, only to be switched to iommu-dma underfoot
once the default domain attachment finally happens, with obviously
disastrous consequences. Even the wonky of_iommu_configure() path is at
risk, since iommu_fwspec_init() will no longer defer client probe as the
instance ops are (necessarily) already registered, and the "replay"
iommu_probe_device() call can see dev->iommu_group already set and so
think there's nothing to do either.
Fortunately we already have the right tool in the right place in the
form of iommu_device_use_default_domain(), which just needs to ensure
that said default domain is actually ready to *be* used. Deferring the
client probe shouldn't have too much impact, given that this only
happens while the IOMMU driver is probing, and thus due to kick the
deferred probe list again once it finishes.
[ Backport: The above is true for mainline, but here we still have
arch_setup_dma_ops() to worry about, which is not replayed if the
default domain happens to be allocated *between* that call and
subsequently reaching iommu_device_use_default_domain(), so we need an
additional earlier check to cover that case. Also we're now back before
the nominal commit 98ac73f99bc4 so we need to tweak the logic to depend
on IOMMU_DMA as well, to avoid falsely deferring on architectures not
using default domains. This then serves us back as far as f188056352bc,
where this specific form of the problem first arises. ]
Reported-by: Charan Teja Kalla <quic_charante(a)quicinc.com>
Fixes: 98ac73f99bc4 ("iommu: Require a default_domain for all iommu drivers")
Fixes: f188056352bc ("iommu: Avoid locking/unlocking for iommu_probe_device()")
Link: https://lore.kernel.org/r/e88b94c9b575034a2c98a48b3d383654cbda7902.17407532…
Signed-off-by: Robin Murphy <robin.murphy(a)arm.com>
---
drivers/iommu/iommu.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 3f1029c0825e..29b48a6a0275 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -566,6 +566,17 @@ int iommu_probe_device(struct device *dev)
mutex_lock(&iommu_probe_device_lock);
ret = __iommu_probe_device(dev, NULL);
mutex_unlock(&iommu_probe_device_lock);
+
+ /*
+ * The dma_configure replay paths need bus_iommu_probe() to
+ * finish before they can call arch_setup_dma_ops()
+ */
+ if (IS_ENABLED(CONFIG_IOMMU_DMA) && !ret && dev->iommu_group) {
+ mutex_lock(&dev->iommu_group->mutex);
+ if (!dev->iommu_group->default_domain)
+ ret = -EPROBE_DEFER;
+ mutex_unlock(&dev->iommu_group->mutex);
+ }
if (ret)
return ret;
@@ -3149,6 +3160,11 @@ int iommu_device_use_default_domain(struct device *dev)
return 0;
mutex_lock(&group->mutex);
+ /* We may race against bus_iommu_probe() finalising groups here */
+ if (!group->default_domain) {
+ ret = -EPROBE_DEFER;
+ goto unlock_out;
+ }
if (group->owner_cnt) {
if (group->owner || !iommu_is_default_domain(group) ||
!xa_empty(&group->pasid_array)) {
--
2.39.2.101.g768bb238c484.dirty
The patch below does not apply to the 6.1-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 44d9b3f584c59a606b521e7274e658d5b866c699
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025042807-emcee-squealing-c022@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 44d9b3f584c59a606b521e7274e658d5b866c699 Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti(a)mev.co.uk>
Date: Tue, 15 Apr 2025 13:39:01 +0100
Subject: [PATCH] comedi: jr3_pci: Fix synchronous deletion of timer
When `jr3_pci_detach()` is called during device removal, it calls
`timer_delete_sync()` to stop the timer, but the timer expiry function
always reschedules the timer, so the synchronization is ineffective.
Call `timer_shutdown_sync()` instead. It does not matter that the timer
expiry function pointer is cleared, because the device is being removed.
Fixes: 07b509e6584a5 ("Staging: comedi: add jr3_pci driver")
Cc: stable <stable(a)kernel.org>
Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk>
Link: https://lore.kernel.org/r/20250415123901.13483-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/comedi/drivers/jr3_pci.c b/drivers/comedi/drivers/jr3_pci.c
index cdc842b32bab..75dce1ff2419 100644
--- a/drivers/comedi/drivers/jr3_pci.c
+++ b/drivers/comedi/drivers/jr3_pci.c
@@ -758,7 +758,7 @@ static void jr3_pci_detach(struct comedi_device *dev)
struct jr3_pci_dev_private *devpriv = dev->private;
if (devpriv)
- timer_delete_sync(&devpriv->timer);
+ timer_shutdown_sync(&devpriv->timer);
comedi_pci_detach(dev);
}
When a CL/CSD job times out, we check if the GPU has made any progress
since the last timeout. If so, instead of resetting the hardware, we skip
the reset and let the timer get rearmed. This gives long-running jobs a
chance to complete.
However, when `timedout_job()` is called, the job in question is removed
from the pending list, which means it won't be automatically freed through
`free_job()`. Consequently, when we skip the reset and keep the job
running, the job won't be freed when it finally completes.
This situation leads to a memory leak, as exposed in [1].
Similarly to commit 704d3d60fec4 ("drm/etnaviv: don't block scheduler when
GPU is still active"), this patch ensures the job is put back on the
pending list when extending the timeout.
Cc: stable(a)vger.kernel.org # 6.0
Link: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12227 [1]
Reported-by: Daivik Bhatia <dtgs1208(a)gmail.com>
Signed-off-by: Maíra Canal <mcanal(a)igalia.com>
---
drivers/gpu/drm/v3d/v3d_sched.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
index b3be08b0ca91..a98dcf9d75b1 100644
--- a/drivers/gpu/drm/v3d/v3d_sched.c
+++ b/drivers/gpu/drm/v3d/v3d_sched.c
@@ -734,11 +734,6 @@ v3d_gpu_reset_for_timeout(struct v3d_dev *v3d, struct drm_sched_job *sched_job)
return DRM_GPU_SCHED_STAT_NOMINAL;
}
-/* If the current address or return address have changed, then the GPU
- * has probably made progress and we should delay the reset. This
- * could fail if the GPU got in an infinite loop in the CL, but that
- * is pretty unlikely outside of an i-g-t testcase.
- */
static enum drm_gpu_sched_stat
v3d_cl_job_timedout(struct drm_sched_job *sched_job, enum v3d_queue q,
u32 *timedout_ctca, u32 *timedout_ctra)
@@ -748,9 +743,16 @@ v3d_cl_job_timedout(struct drm_sched_job *sched_job, enum v3d_queue q,
u32 ctca = V3D_CORE_READ(0, V3D_CLE_CTNCA(q));
u32 ctra = V3D_CORE_READ(0, V3D_CLE_CTNRA(q));
+ /* If the current address or return address have changed, then the GPU
+ * has probably made progress and we should delay the reset. This
+ * could fail if the GPU got in an infinite loop in the CL, but that
+ * is pretty unlikely outside of an i-g-t testcase.
+ */
if (*timedout_ctca != ctca || *timedout_ctra != ctra) {
*timedout_ctca = ctca;
*timedout_ctra = ctra;
+
+ list_add(&sched_job->list, &sched_job->sched->pending_list);
return DRM_GPU_SCHED_STAT_NOMINAL;
}
@@ -790,11 +792,13 @@ v3d_csd_job_timedout(struct drm_sched_job *sched_job)
struct v3d_dev *v3d = job->base.v3d;
u32 batches = V3D_CORE_READ(0, V3D_CSD_CURRENT_CFG4(v3d->ver));
- /* If we've made progress, skip reset and let the timer get
- * rearmed.
+ /* If we've made progress, skip reset, add the job to the pending
+ * list, and let the timer get rearmed.
*/
if (job->timedout_batches != batches) {
job->timedout_batches = batches;
+
+ list_add(&sched_job->list, &sched_job->sched->pending_list);
return DRM_GPU_SCHED_STAT_NOMINAL;
}
--
2.49.0
commit 8006aff15516a170640239c5a8e6696c0ba18d8e upstream.
According to the review by Bill Cox [1], the Atmel SHA204A random number
generator produces random numbers with very low entropy.
Set the lowest possible entropy for this chip just to be safe.
[1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
Fixes: da001fb651b00e1d ("crypto: atmel-i2c - add support for SHA204A random number generator")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Marek Behún <kabel(a)kernel.org>
Acked-by: Ard Biesheuvel <ardb(a)kernel.org>
Reviewed-by: Linus Walleij <linus.walleij(a)linaro.org>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
[ rebased for 5.4 ]
Signed-off-by: Marek Behún <kabel(a)kernel.org>
---
drivers/crypto/atmel-sha204a.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index c96c14e7dab1..0ef92109ce22 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -107,7 +107,12 @@ static int atmel_sha204a_probe(struct i2c_client *client,
i2c_priv->hwrng.name = dev_name(&client->dev);
i2c_priv->hwrng.read = atmel_sha204a_rng_read;
- i2c_priv->hwrng.quality = 1024;
+
+ /*
+ * According to review by Bill Cox [1], this HWRNG has very low entropy.
+ * [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
+ */
+ i2c_priv->hwrng.quality = 1;
ret = devm_hwrng_register(&client->dev, &i2c_priv->hwrng);
if (ret)
--
2.49.0
commit 8006aff15516a170640239c5a8e6696c0ba18d8e upstream.
According to the review by Bill Cox [1], the Atmel SHA204A random number
generator produces random numbers with very low entropy.
Set the lowest possible entropy for this chip just to be safe.
[1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
Fixes: da001fb651b00e1d ("crypto: atmel-i2c - add support for SHA204A random number generator")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Marek Behún <kabel(a)kernel.org>
Acked-by: Ard Biesheuvel <ardb(a)kernel.org>
Reviewed-by: Linus Walleij <linus.walleij(a)linaro.org>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
[ rebased for 5.10 ]
Signed-off-by: Marek Behún <kabel(a)kernel.org>
---
drivers/crypto/atmel-sha204a.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index c96c14e7dab1..0ef92109ce22 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -107,7 +107,12 @@ static int atmel_sha204a_probe(struct i2c_client *client,
i2c_priv->hwrng.name = dev_name(&client->dev);
i2c_priv->hwrng.read = atmel_sha204a_rng_read;
- i2c_priv->hwrng.quality = 1024;
+
+ /*
+ * According to review by Bill Cox [1], this HWRNG has very low entropy.
+ * [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
+ */
+ i2c_priv->hwrng.quality = 1;
ret = devm_hwrng_register(&client->dev, &i2c_priv->hwrng);
if (ret)
--
2.49.0
commit 8006aff15516a170640239c5a8e6696c0ba18d8e upstream.
According to the review by Bill Cox [1], the Atmel SHA204A random number
generator produces random numbers with very low entropy.
Set the lowest possible entropy for this chip just to be safe.
[1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
Fixes: da001fb651b00e1d ("crypto: atmel-i2c - add support for SHA204A random number generator")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Marek Behún <kabel(a)kernel.org>
Acked-by: Ard Biesheuvel <ardb(a)kernel.org>
Reviewed-by: Linus Walleij <linus.walleij(a)linaro.org>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
[ rebased for 5.15 ]
Signed-off-by: Marek Behún <kabel(a)kernel.org>
---
drivers/crypto/atmel-sha204a.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index c96c14e7dab1..0ef92109ce22 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -107,7 +107,12 @@ static int atmel_sha204a_probe(struct i2c_client *client,
i2c_priv->hwrng.name = dev_name(&client->dev);
i2c_priv->hwrng.read = atmel_sha204a_rng_read;
- i2c_priv->hwrng.quality = 1024;
+
+ /*
+ * According to review by Bill Cox [1], this HWRNG has very low entropy.
+ * [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
+ */
+ i2c_priv->hwrng.quality = 1;
ret = devm_hwrng_register(&client->dev, &i2c_priv->hwrng);
if (ret)
--
2.49.0
commit 8006aff15516a170640239c5a8e6696c0ba18d8e upstream.
According to the review by Bill Cox [1], the Atmel SHA204A random number
generator produces random numbers with very low entropy.
Set the lowest possible entropy for this chip just to be safe.
[1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
Fixes: da001fb651b00e1d ("crypto: atmel-i2c - add support for SHA204A random number generator")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Marek Behún <kabel(a)kernel.org>
Acked-by: Ard Biesheuvel <ardb(a)kernel.org>
Reviewed-by: Linus Walleij <linus.walleij(a)linaro.org>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
[ rebased for 6.1 ]
Signed-off-by: Marek Behún <kabel(a)kernel.org>
---
drivers/crypto/atmel-sha204a.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index a84b657598c6..51738c730717 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -107,7 +107,12 @@ static int atmel_sha204a_probe(struct i2c_client *client,
i2c_priv->hwrng.name = dev_name(&client->dev);
i2c_priv->hwrng.read = atmel_sha204a_rng_read;
- i2c_priv->hwrng.quality = 1024;
+
+ /*
+ * According to review by Bill Cox [1], this HWRNG has very low entropy.
+ * [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
+ */
+ i2c_priv->hwrng.quality = 1;
ret = devm_hwrng_register(&client->dev, &i2c_priv->hwrng);
if (ret)
--
2.49.0
The patch below does not apply to the 6.6-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 44d9b3f584c59a606b521e7274e658d5b866c699
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025042806-speculate-arose-b5b8@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 44d9b3f584c59a606b521e7274e658d5b866c699 Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti(a)mev.co.uk>
Date: Tue, 15 Apr 2025 13:39:01 +0100
Subject: [PATCH] comedi: jr3_pci: Fix synchronous deletion of timer
When `jr3_pci_detach()` is called during device removal, it calls
`timer_delete_sync()` to stop the timer, but the timer expiry function
always reschedules the timer, so the synchronization is ineffective.
Call `timer_shutdown_sync()` instead. It does not matter that the timer
expiry function pointer is cleared, because the device is being removed.
Fixes: 07b509e6584a5 ("Staging: comedi: add jr3_pci driver")
Cc: stable <stable(a)kernel.org>
Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk>
Link: https://lore.kernel.org/r/20250415123901.13483-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/comedi/drivers/jr3_pci.c b/drivers/comedi/drivers/jr3_pci.c
index cdc842b32bab..75dce1ff2419 100644
--- a/drivers/comedi/drivers/jr3_pci.c
+++ b/drivers/comedi/drivers/jr3_pci.c
@@ -758,7 +758,7 @@ static void jr3_pci_detach(struct comedi_device *dev)
struct jr3_pci_dev_private *devpriv = dev->private;
if (devpriv)
- timer_delete_sync(&devpriv->timer);
+ timer_shutdown_sync(&devpriv->timer);
comedi_pci_detach(dev);
}