Patch "virtio_net: Do not send RSS key if it is not supported" has been added to the 6.8-stable tree

2024-04-14 Thread gregkh


This is a note to let you know that I've just added the patch titled

virtio_net: Do not send RSS key if it is not supported

to the 6.8-stable tree which can be found at:

http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
 virtio_net-do-not-send-rss-key-if-it-is-not-supported.patch
and it can be found in the queue-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let  know about it.


>From 059a49aa2e25c58f90b50151f109dd3c4cdb3a47 Mon Sep 17 00:00:00 2001
From: Breno Leitao 
Date: Wed, 3 Apr 2024 08:43:12 -0700
Subject: virtio_net: Do not send RSS key if it is not supported

From: Breno Leitao 

commit 059a49aa2e25c58f90b50151f109dd3c4cdb3a47 upstream.

There is a bug when setting the RSS options in virtio_net that can break
the whole machine, getting the kernel into an infinite loop.

Running the following command in any QEMU virtual machine with virtionet
will reproduce this problem:

# ethtool -X eth0  hfunc toeplitz

This is how the problem happens:

1) ethtool_set_rxfh() calls virtnet_set_rxfh()

2) virtnet_set_rxfh() calls virtnet_commit_rss_command()

3) virtnet_commit_rss_command() populates 4 entries for the rss
scatter-gather

4) Since the command above does not have a key, then the last
scatter-gatter entry will be zeroed, since rss_key_size == 0.
sg_buf_size = vi->rss_key_size;

5) This buffer is passed to qemu, but qemu is not happy with a buffer
with zero length, and do the following in virtqueue_map_desc() (QEMU
function):

  if (!sz) {
  virtio_error(vdev, "virtio: zero sized buffers are not allowed");

6) virtio_error() (also QEMU function) set the device as broken

vdev->broken = true;

7) Qemu bails out, and do not repond this crazy kernel.

8) The kernel is waiting for the response to come back (function
virtnet_send_command())

9) The kernel is waiting doing the following :

  while (!virtqueue_get_buf(vi->cvq, &tmp) &&
 !virtqueue_is_broken(vi->cvq))
  cpu_relax();

10) None of the following functions above is true, thus, the kernel
loops here forever. Keeping in mind that virtqueue_is_broken() does
not look at the qemu `vdev->broken`, so, it never realizes that the
vitio is broken at QEMU side.

Fix it by not sending RSS commands if the feature is not available in
the device.

Fixes: c7114b1249fa ("drivers/net/virtio_net: Added basic RSS support.")
Cc: sta...@vger.kernel.org
Cc: qemu-devel@nongnu.org
Signed-off-by: Breno Leitao 
Reviewed-by: Heng Qi 
Reviewed-by: Xuan Zhuo 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/net/virtio_net.c |   26 ++
 1 file changed, 22 insertions(+), 4 deletions(-)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3768,6 +3768,7 @@ static int virtnet_set_rxfh(struct net_d
struct netlink_ext_ack *extack)
 {
struct virtnet_info *vi = netdev_priv(dev);
+   bool update = false;
int i;
 
if (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
@@ -3775,13 +3776,28 @@ static int virtnet_set_rxfh(struct net_d
return -EOPNOTSUPP;
 
if (rxfh->indir) {
+   if (!vi->has_rss)
+   return -EOPNOTSUPP;
+
for (i = 0; i < vi->rss_indir_table_size; ++i)
vi->ctrl->rss.indirection_table[i] = rxfh->indir[i];
+   update = true;
}
-   if (rxfh->key)
+
+   if (rxfh->key) {
+   /* If either _F_HASH_REPORT or _F_RSS are negotiated, the
+* device provides hash calculation capabilities, that is,
+* hash_key is configured.
+*/
+   if (!vi->has_rss && !vi->has_rss_hash_report)
+   return -EOPNOTSUPP;
+
memcpy(vi->ctrl->rss.key, rxfh->key, vi->rss_key_size);
+   update = true;
+   }
 
-   virtnet_commit_rss_command(vi);
+   if (update)
+   virtnet_commit_rss_command(vi);
 
return 0;
 }
@@ -4686,13 +4702,15 @@ static int virtnet_probe(struct virtio_d
if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
vi->has_rss_hash_report = true;
 
-   if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
+   if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) {
vi->has_rss = true;
 
-   if (vi->has_rss || vi->has_rss_hash_report) {
vi->rss_indir_table_size =
virtio_cread16(vdev, offsetof(struct virtio_net_config,
rss_max_indirection_table_length));
+   }
+
+   if (vi->has_rss || vi->has_rss_hash_report) {
vi->rss_key_size =
virtio_cread8(vdev, offsetof(struct virtio_net_config, 
rss_max_key_size));
 


Patches currently in stable-queue which might be from lei...@debian.org are

queue-6.

Patch "virtio_net: Do not send RSS key if it is not supported" has been added to the 6.6-stable tree

2024-04-23 Thread gregkh


This is a note to let you know that I've just added the patch titled

virtio_net: Do not send RSS key if it is not supported

to the 6.6-stable tree which can be found at:

http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
 virtio_net-do-not-send-rss-key-if-it-is-not-supported.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let  know about it.


>From 059a49aa2e25c58f90b50151f109dd3c4cdb3a47 Mon Sep 17 00:00:00 2001
From: Breno Leitao 
Date: Wed, 3 Apr 2024 08:43:12 -0700
Subject: virtio_net: Do not send RSS key if it is not supported

From: Breno Leitao 

commit 059a49aa2e25c58f90b50151f109dd3c4cdb3a47 upstream.

There is a bug when setting the RSS options in virtio_net that can break
the whole machine, getting the kernel into an infinite loop.

Running the following command in any QEMU virtual machine with virtionet
will reproduce this problem:

# ethtool -X eth0  hfunc toeplitz

This is how the problem happens:

1) ethtool_set_rxfh() calls virtnet_set_rxfh()

2) virtnet_set_rxfh() calls virtnet_commit_rss_command()

3) virtnet_commit_rss_command() populates 4 entries for the rss
scatter-gather

4) Since the command above does not have a key, then the last
scatter-gatter entry will be zeroed, since rss_key_size == 0.
sg_buf_size = vi->rss_key_size;

5) This buffer is passed to qemu, but qemu is not happy with a buffer
with zero length, and do the following in virtqueue_map_desc() (QEMU
function):

  if (!sz) {
  virtio_error(vdev, "virtio: zero sized buffers are not allowed");

6) virtio_error() (also QEMU function) set the device as broken

vdev->broken = true;

7) Qemu bails out, and do not repond this crazy kernel.

8) The kernel is waiting for the response to come back (function
virtnet_send_command())

9) The kernel is waiting doing the following :

  while (!virtqueue_get_buf(vi->cvq, &tmp) &&
 !virtqueue_is_broken(vi->cvq))
  cpu_relax();

10) None of the following functions above is true, thus, the kernel
loops here forever. Keeping in mind that virtqueue_is_broken() does
not look at the qemu `vdev->broken`, so, it never realizes that the
vitio is broken at QEMU side.

Fix it by not sending RSS commands if the feature is not available in
the device.

Fixes: c7114b1249fa ("drivers/net/virtio_net: Added basic RSS support.")
Cc: sta...@vger.kernel.org
Cc: qemu-devel@nongnu.org
Signed-off-by: Breno Leitao 
Reviewed-by: Heng Qi 
Reviewed-by: Xuan Zhuo 
Signed-off-by: David S. Miller 
Signed-off-by: Vlad Poenaru 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/net/virtio_net.c |   25 +
 1 file changed, 21 insertions(+), 4 deletions(-)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3570,19 +3570,34 @@ static int virtnet_get_rxfh(struct net_d
 static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 
*key, const u8 hfunc)
 {
struct virtnet_info *vi = netdev_priv(dev);
+   bool update = false;
int i;
 
if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
return -EOPNOTSUPP;
 
if (indir) {
+   if (!vi->has_rss)
+   return -EOPNOTSUPP;
+
for (i = 0; i < vi->rss_indir_table_size; ++i)
vi->ctrl->rss.indirection_table[i] = indir[i];
+   update = true;
}
-   if (key)
+   if (key) {
+   /* If either _F_HASH_REPORT or _F_RSS are negotiated, the
+* device provides hash calculation capabilities, that is,
+* hash_key is configured.
+*/
+   if (!vi->has_rss && !vi->has_rss_hash_report)
+   return -EOPNOTSUPP;
+
memcpy(vi->ctrl->rss.key, key, vi->rss_key_size);
+   update = true;
+   }
 
-   virtnet_commit_rss_command(vi);
+   if (update)
+   virtnet_commit_rss_command(vi);
 
return 0;
 }
@@ -4491,13 +4506,15 @@ static int virtnet_probe(struct virtio_d
if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
vi->has_rss_hash_report = true;
 
-   if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
+   if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) {
vi->has_rss = true;
 
-   if (vi->has_rss || vi->has_rss_hash_report) {
vi->rss_indir_table_size =
virtio_cread16(vdev, offsetof(struct virtio_net_config,
rss_max_indirection_table_length));
+   }
+
+   if (vi->has_rss || vi->has_rss_hash_report) {
vi->rss_key_size =
virtio_cread8(vdev, offsetof(struct virtio_net_config, 
rss_max_key_size));
 


Patches currently in stable-queue which might be from lei...@debian.org are

queue-6.6/v

Patch "virtio_net: Do not send RSS key if it is not supported" has been added to the 6.1-stable tree

2024-04-29 Thread gregkh


This is a note to let you know that I've just added the patch titled

virtio_net: Do not send RSS key if it is not supported

to the 6.1-stable tree which can be found at:

http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
 virtio_net-do-not-send-rss-key-if-it-is-not-supported.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let  know about it.


>From 059a49aa2e25c58f90b50151f109dd3c4cdb3a47 Mon Sep 17 00:00:00 2001
From: Breno Leitao 
Date: Wed, 3 Apr 2024 08:43:12 -0700
Subject: virtio_net: Do not send RSS key if it is not supported

From: Breno Leitao 

commit 059a49aa2e25c58f90b50151f109dd3c4cdb3a47 upstream.

There is a bug when setting the RSS options in virtio_net that can break
the whole machine, getting the kernel into an infinite loop.

Running the following command in any QEMU virtual machine with virtionet
will reproduce this problem:

# ethtool -X eth0  hfunc toeplitz

This is how the problem happens:

1) ethtool_set_rxfh() calls virtnet_set_rxfh()

2) virtnet_set_rxfh() calls virtnet_commit_rss_command()

3) virtnet_commit_rss_command() populates 4 entries for the rss
scatter-gather

4) Since the command above does not have a key, then the last
scatter-gatter entry will be zeroed, since rss_key_size == 0.
sg_buf_size = vi->rss_key_size;

5) This buffer is passed to qemu, but qemu is not happy with a buffer
with zero length, and do the following in virtqueue_map_desc() (QEMU
function):

  if (!sz) {
  virtio_error(vdev, "virtio: zero sized buffers are not allowed");

6) virtio_error() (also QEMU function) set the device as broken

vdev->broken = true;

7) Qemu bails out, and do not repond this crazy kernel.

8) The kernel is waiting for the response to come back (function
virtnet_send_command())

9) The kernel is waiting doing the following :

  while (!virtqueue_get_buf(vi->cvq, &tmp) &&
 !virtqueue_is_broken(vi->cvq))
  cpu_relax();

10) None of the following functions above is true, thus, the kernel
loops here forever. Keeping in mind that virtqueue_is_broken() does
not look at the qemu `vdev->broken`, so, it never realizes that the
vitio is broken at QEMU side.

Fix it by not sending RSS commands if the feature is not available in
the device.

Fixes: c7114b1249fa ("drivers/net/virtio_net: Added basic RSS support.")
Cc: sta...@vger.kernel.org
Cc: qemu-devel@nongnu.org
Signed-off-by: Breno Leitao 
Reviewed-by: Heng Qi 
Reviewed-by: Xuan Zhuo 
Signed-off-by: David S. Miller 
Signed-off-by: Konstantin Ovsepian 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/net/virtio_net.c |   26 ++
 1 file changed, 22 insertions(+), 4 deletions(-)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2948,19 +2948,35 @@ static int virtnet_get_rxfh(struct net_d
 static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 
*key, const u8 hfunc)
 {
struct virtnet_info *vi = netdev_priv(dev);
+   bool update = false;
int i;
 
if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
return -EOPNOTSUPP;
 
if (indir) {
+   if (!vi->has_rss)
+   return -EOPNOTSUPP;
+
for (i = 0; i < vi->rss_indir_table_size; ++i)
vi->ctrl->rss.indirection_table[i] = indir[i];
+   update = true;
}
-   if (key)
+
+   if (key) {
+   /* If either _F_HASH_REPORT or _F_RSS are negotiated, the
+* device provides hash calculation capabilities, that is,
+* hash_key is configured.
+*/
+   if (!vi->has_rss && !vi->has_rss_hash_report)
+   return -EOPNOTSUPP;
+
memcpy(vi->ctrl->rss.key, key, vi->rss_key_size);
+   update = true;
+   }
 
-   virtnet_commit_rss_command(vi);
+   if (update)
+   virtnet_commit_rss_command(vi);
 
return 0;
 }
@@ -3852,13 +3868,15 @@ static int virtnet_probe(struct virtio_d
if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
vi->has_rss_hash_report = true;
 
-   if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
+   if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) {
vi->has_rss = true;
 
-   if (vi->has_rss || vi->has_rss_hash_report) {
vi->rss_indir_table_size =
virtio_cread16(vdev, offsetof(struct virtio_net_config,
rss_max_indirection_table_length));
+   }
+
+   if (vi->has_rss || vi->has_rss_hash_report) {
vi->rss_key_size =
virtio_cread8(vdev, offsetof(struct virtio_net_config, 
rss_max_key_size));
 


Patches currently in stable-queue which might be from lei...@debian.org are

q