Errors in the implementation of online resize in ext4 caused failures of ploop resize operations.
Potential kernel crash in cbt_flush_cpu_cache().
Ploop: integer overflow in the implementation of direct IO could lead to errors when resizing the ploop image.
Incorrect accounting of network namespaces in the error paths in copy_net_ns().
Use-after-free in the implementation of the shared memory.
A flaw was found in the implementation of the shared memory in the Linux kernel. shm_mmap() function did not always check if the underlying file structures were valid, which could lead to use-after-free. A local unprivileged user could exploit this to crash the kernel by executing a special sequence of system calls.
Use-after-free due to race condition in AF_PACKET implementation.
It was discovered that a race condition between packet_do_bind() and packet_notifier() in the implementation of AF_PACKET could lead to use-after-free. An unprivileged user on the host or in a container could exploit this to crash the kernel or, potentially, to escalate their privileges in the system.
Potential kernel crash in ext4_close_pfcache().
Integer overflow in create_elf_tables() function.
An integer overflow flaw was found in create_elf_tables(). An unprivileged local user with access to SUID (or otherwise privileged) binary could use this flaw to escalate their privileges on the system.
Bypass of the size restriction on the arguments and environment variables of a process.
The Linux kernel imposes a size limit on the memory needed to store the arguments and environment variables of a process, 1/4 of the maximum stack size (RLIMIT_STACK). However, the pointers to these data were not taken into account, which allowed attackers to bypass the limit and even exhaust the stack of the process.
Kernel crash in __run_hrtimer().
It was found that the implementation of high resolution timers ('hrtimer' subsystem) did not handle the situation when a timer was started simultaneously with its restart in another thread. As a result, a BUG_ON() could trigger in __run_hrtimer() leading to kernel crash.
Soft lockup in xfrm_policy_flush().
If an error occurred during execution of xfrm_net_init() when a new network namespace was created, xfrm_policy_lock could remain uninitialized. As a result, soft lockup could happen in xfrm_policy_flush() if it tried to acquire the lock after that.
ploop: kernel crash in dio_open().
It was found that the implementation of ploop did not handle errors reported by kthread_create() properly. This could lead to a kernel crash in dio_open().
Containers with NFS mounts failed to migrate: CRIU complained about nfs/clntX files.
It was discovered that a container with NFS mounts could keep the files /var/lib/nfs/rpc_pipefs/nfs/clntX open, even if no NFS server was running there. As a result, CRIU reported errors when the users tried to migrate the container.
File systems: insufficient error handling in sget() could lead to excessive memory consumption.
sunrpc: potential kernel crash (use after free) in svc_process_common().
Potential out-of-bounds read in fuse_dev_splice_write().
Processes could get stuck in an unkillable state when using large FUSE KIO messages.
It was found that rpc_get_hdr() function from 'fuse_kio_pcs' module did not return valid values in 'msg_size' in some cases. As a result, the processes using large FUSE KIO messages could get stuck in an unkillable state.