A specially crafted program running in a container could make certain processes on the host hang (denial of service).
Kernel crash in mem_cgroup_from_cont() due to a race between memory reclaim and offlining of a cgroup.
Kernel crash due to an incorrect BUG_ON() assertion in move_freepages().
ploop: certain operations with large ploop images could lead to a division by zero in __map_extent_bmap().
nfsd: Potential kernel crash in nfs4_put_stid().
'ploop grow' operation could fail in certain cases if the ploop image file contained holes.
Processes being killed by the OOM killer could continue consuming memory.
If a process running in a container performed large allocations of kernel memory, this could hit the memory limit for the container and trigger the OOM killer. It was discovered, however, that the process being killed by it could continue consuming memory for some time. This could lead to out of memory conditions on the host.
'ploop snapshot' operation could hang in certain cases.
bcache: Potential kernel crash when using RAID1 as a backing device.
ploop: Potential kernel crash or data corruption during backups due to racy operations with lockout data.
netfilter/ipset: excessive memory consumption leading to a denial of service.
If was discovered that not all memory allocated for ipset-related data was properly accounted for. An attacker could exploit it from a container to consume lots of kernel memory, making the host system unusable (denial of service).
NFS v4: potential memory corruption on the client system when processing security attributes.
It was discovered that a buffer overflow and memory corruption were possible if a system tried to mount an NFS v4 share where the files had security labels in the file attributes. An attacker would need to control the NFS server and make it send a specific series of responses to trigger the issue. The issue allows the attacker to crash the kernel on the client system or, potentially, escalate their privileges there.
netfilter: kernel crash due to a buffer overflow in ctnetlink_parse_tuple_filter().
It was discovered that a local attacker could pass a specially crafted configuration of conntrack to the kernel to cause a buffer overflow in ctnetlink_parse_tuple_filter() function. As a result, the kernel could crash.
The metadata validator in XFS may flag an inode with a valid extended attribute as corrupt.
A failure of the file system metadata validator in XFS can cause an inode with a valid, user-creatable extended attribute to be flagged as corrupt. This can lead to the filesystem being shutdown, or otherwise rendered inaccessible until it is remounted, leading to a denial of service.
Potential kernel crash (use-after-free) in the implementation of usermode helpers.
A race condition was discovered in the implementation of usermode helpers in the kernel. An attacker could exploit it from a container to cause a denial-of-service (kernel crash due to a use-after-free), or, potentially, to escalate their privileges in the system.
nf_tables: kernel crash in nf_tables_getset().
It was discovered that the implementation of nf_tables did not properly validate certain parameters. An attacker could exploit this from a container to cause a kernel crash: NULL pointer dereference or a general protection fault in nf_tables_getset().
nfnetlink: potential kernel crash (skb_over_panic) in skb_put().
It was discovered that nfnetlink subsystem did not properly validate certain messages. An attacker could exploit this from a container to cause a kernel crash: skb_over_panic in skb_put().
Memory reclaim could become too slow leading to high LA on the nodes.
The original fix for PSBM-99181 and related issues introduced a problem: management of shrinkers used to reclaim memory could become very inefficient in certain cases, causing higher load on the affected nodes.
nf_conntrack: potential kernel crash in nf_ct_gre_keymap_destroy().
memcg: the limit on page cache (memory.cache.limit_in_bytes) could be exceeded significantly in certain cases.
File system of a container becomes read-only, __ext4_handle_dirty_metadata() reports error 28.
Possible use-after-free error due to a race condition in cdev_get().
It was discovered that use-after-free condition was possible in cdev_get() if multiple processes simultaneously accessed a character device in a certain way. A local attacker could potentially exploit this to crash the kernel.
memcg: kernel crash in memcg_destroy_kmem_caches() caused by unbalanced css_tryget/css_put operations.
Hard lockup and kernel crash caused by incorrect locking in calc_load_ve().
af_packet: potential soft lockup in case of certain errors when using TPACKET_V3.
It was found that if TPACKET_V3 was used and the kernel failed to obtain certain settings from a relevant network device, the retirement timer could be set incorrectly in the implementation AF_PACKET protocol. This could result in soft lockups and excessive CPU usage.
Core dumps of some processes could contain uninitialized kernel data.
It was discovered that core dumps of userspace processes could contain copies of uninitialized kernel memory areas in certain cases. Although it is difficult for an attacker to control what data is in these areas, this issue, in theory, could be used to obtain sensitive information from the kernel.
ploop: kernel crash (division by zero) in purge_lru_warn().
Denial of service by corrupting mountpoint reference counter.
It was discovered that a race condition was possible between pivot_root() and put_mountpoint() operations. A local unprivileged attacker could exploit this to corrupt mountpoint reference counter and cause a denial of service (kernel crash).
futex: potential system hang due to a missing unlock operation in the error path of futex_wait_requeue_pi().