Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

gve: prevent ethtool ops after shutdown

A crash can occur if an ethtool operation is invoked after shutdown() is called.

shutdown() is invoked during system shutdown to stop DMA operations without performing expensive deallocations. It is discouraged to unregister the netdev in this path, so the device may still be visible to userspace and kernel helpers.

In gve, shutdown() tears down most internal data structures. If an ethtool operation is dispatched after shutdown(), it will dereference freed or NULL pointers, leading to a kernel panic. While graceful shutdown normally quiesces userspace before invoking the reboot syscall, forced shutdowns (as observed on GCP VMs) can still trigger this path.

Fix by calling netif_device_detach() in shutdown(). This marks the device as detached so the ethtool ioctl handler will skip dispatching operations to the driver.

In the Linux kernel, the following vulnerability has been resolved:

gve: prevent ethtool ops after shutdown

A crash can occur if an ethtool operation is invoked after shutdown() is called.

shutdown() is invoked during system shutdown to stop DMA operations without performing expensive deallocations. It is discouraged to unregister the netdev in this path, so the device may still be visible to userspace and kernel helpers.

In gve, shutdown() tears down most internal data structures. If an ethtool operation is dispatched after shutdown(), it will dereference freed or NULL pointers, leading to a kernel panic. While graceful shutdown normally quiesces userspace before invoking the reboot syscall, forced shutdowns (as observed on GCP VMs) can still trigger this path.

Fix by calling netif_device_detach() in shutdown(). This marks the device as detached so the ethtool ioctl handler will skip dispatching operations to the driver.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check link_res->hpo_dp_link_enc before using it [WHAT & HOW] Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res without initializing hpo_dp_link_enc and it is necessary to check for null before dereferencing. This fixes 2 FORWARD_NULL issues reported by Coverity. In the Linux kernel, the following vulnerability has been resolved:

fs: relax assertions on failure to encode file handles

Encoding file handles is usually performed by a filesystem >encode_fh() method that may fail for various reasons.

The legacy users of exportfs_encode_fh(), namely, nfsd and name_to_handle_at(2) syscall are ready to cope with the possibility of failure to encode a file handle.

There are a few other users of exportfs_encode_{fh,fid}() that currently have a WARN_ON() assertion when ->encode_fh() fails. Relax those assertions because they are wrong.

The second linked bug report states commit 16aac5ad1fa9 ("ovl: support encoding non-decodable file handles") in v6.6 as the regressing commit, but this is not accurate.

The aforementioned commit only increases the chances of the assertion and allows triggering the assertion with the reproducer using overlayfs, inotify and drop_caches.

Triggering this assertion was always possible with other filesystems and other reasons of ->encode_fh() failures and more particularly, it was also possible with the exact same reproducer using overlay…

Security update for the Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check link_res->hpo_dp_link_enc before using it [WHAT & HOW] Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res without initializing hpo_dp_link_enc and it is necessary to check for null before dereferencing. This fixes 2 FORWARD_NULL issues reported by Coverity. In the Linux kernel, the following vulnerability has been resolved:

fs: relax assertions on failure to encode file handles

Encoding file handles is usually performed by a filesystem >encode_fh() method that may fail for various reasons.

The legacy users of exportfs_encode_fh(), namely, nfsd and name_to_handle_at(2) syscall are ready to cope with the possibility of failure to encode a file handle.

There are a few other users of exportfs_encode_{fh,fid}() that currently have a WARN_ON() assertion when ->encode_fh() fails. Relax those assertions because they are wrong.

The second linked bug report states commit 16aac5ad1fa9 ("ovl: support encoding non-decodable file handles") in v6.6 as the regressing commit, but this is not accurate.

The aforementioned commit only increases the chances of the assertion and allows triggering the assertion with the reproducer using overlayfs, inotify and drop_caches.

Triggering this assertion was always possible with other filesystems and other reasons of ->encode_fh() failures and more particularly, it was also possible with the exact same reproducer using overlay…

Security update for the Linux Kernel

Affected: Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:Pro:18.04:LTS: linux-gcp-4.15, Ubuntu:18.04:LTS: linux-gcp-5.3 and 134 more

In the Linux kernel, the following vulnerability has been resolved: gve: prevent ethtool ops after shutdown A crash can occur if an ethtool operation is invoked after shutdown() is called. shutdown() is invoked during system shutdown to stop DMA operations without performing expensive deallocations. It is discouraged to unregister the netdev in this path, so the device may still be visible to userspace and kernel helpers. In gve, shutdown() tears down most internal data structures. If an ethtool operation is dispatched after shutdown(), it will dereference freed or NULL pointers, leading to a kernel panic. While graceful shutdown normally quiesces userspace before invoking the reboot syscall, forced shutdowns (as observed on GCP VMs) can still trigger this path. Fix by calling netif_device_detach() in shutdown(). This marks the device as detached so the ethtool ioctl handler will skip dispatching operations to the driver.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder nicht näher spezifizierte Auswirkungen zu erzielen.