Linux Linux Kernel 2.1.51

The Linux kernel through 5.7.11 allows remote attackers to make observations that help to obtain sensitive information about the internal state of the network RNG, aka CID-f227e3ec3b5c. This is related to drivers/char/random.c and kernel/time/timer.c.

An issue was discovered in the Linux kernel 5.5 through 5.7.9, as used in Xen through 4.13.x for x86 PV guests. An attacker may be granted the I/O port permissions of an unrelated task. This occurs because tss_invalidate_io_bitmap mishandling causes a loss of synchronization between the I/O bitmaps of TSS and Xen, aka CID-cadfad870154.

An issue was discovered in drivers/acpi/acpi_configfs.c in the Linux kernel before 5.7.7. Injection of malicious ACPI tables via configfs could be used by attackers to bypass lockdown and secure boot restrictions, aka CID-75b0cea7bf30.

An issue was discovered in drivers/firmware/efi/efi.c in the Linux kernel before 5.4. Incorrect access permissions for the efivar_ssdt ACPI variable could be used by attackers to bypass lockdown or secure boot restrictions, aka CID-1957a85b0032.

A flaw was found in the fix for CVE-2019-11135, in the Linux upstream kernel versions before 5.5 where, the way Intel CPUs handle speculative execution of instructions when a TSX Asynchronous Abort (TAA) error occurs. When a guest is running on a host CPU affected by the TAA flaw (TAA_NO=0), but is not affected by the MDS issue (MDS_NO=1), the guest was to clear the affected buffers by using a VERW instruction mechanism. But when the MDS_NO=1 bit was exported to the guests, the guests did not use the VERW mechanism to clear the affected buffers. This issue affects guests running on Cascade Lake CPUs and requires that host has 'TSX' enabled. Confidentiality of data is the highest threat associated with this vulnerability.

In the Linux kernel through 5.7.6, usbtest_disconnect in drivers/usb/misc/usbtest.c has a memory leak, aka CID-28ebeb8db770.

In the Linux kernel before 5.4.16, a race condition in tty->disc_data handling in the slip and slcan line discipline could lead to a use-after-free, aka CID-0ace17d56824. This affects drivers/net/slip/slip.c and drivers/net/can/slcan.c.

** DISPUTED ** An issue was discovered in the Linux kernel through 5.7.1. drivers/tty/vt/keyboard.c has an integer overflow if k_ascii is called several times in a row, aka CID-b86dab054059. NOTE: Members in the community argue that the integer overflow does not lead to a security issue in this case.

A flaw was found in the Linux Kernel in versions after 4.5-rc1 in the way mremap handled DAX Huge Pages. This flaw allows a local attacker with access to a DAX enabled storage to escalate their privileges on the system.

An issue was discovered in the Linux kernel before 5.4.7. The prb_calc_retire_blk_tmo() function in net/packet/af_packet.c can result in a denial of service (CPU consumption and soft lockup) in a certain failure case involving TPACKET_V3, aka CID-b43d1f9f7067.

An issue was discovered in the Linux kernel before 5.0.6. In rx_queue_add_kobject() and netdev_queue_add_kobject() in net/core/net-sysfs.c, a reference count is mishandled, aka CID-a3e23f719f5c.

go7007_snd_init in drivers/media/usb/go7007/snd-go7007.c in the Linux kernel before 5.6 does not call snd_card_free for a failure path, which causes a memory leak, aka CID-9453264ef586.

An issue was discovered in the Linux kernel before 5.2. There is a NULL pointer dereference in tw5864_handle_frame() in drivers/media/pci/tw5864/tw5864-video.c, which may cause denial of service, aka CID-2e7682ebfc75.

A NULL pointer dereference flaw was found in the Linux kernel's SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel, resulting in a denial of service.

gadget_dev_desc_UDC_store in drivers/usb/gadget/configfs.c in the Linux kernel through 5.6.13 relies on kstrdup without considering the possibility of an internal '\0' value, which allows attackers to trigger an out-of-bounds read, aka CID-15753588bcd4.

The VFIO PCI driver in the Linux kernel through 5.6.13 mishandles attempts to access disabled memory space.

A signal access-control issue was discovered in the Linux kernel before 5.6.5, aka CID-7395ea4e65c2. Because exec_id in include/linux/sched.h is only 32 bits, an integer overflow can interfere with a do_notify_parent protection mechanism. A child process can send an arbitrary signal to a parent process in a different security domain. Exploitation limitations include the amount of elapsed time before an integer overflow occurs, and the lack of scenarios where signals to a parent process present a substantial operational threat.

An issue was discovered in the Linux kernel through 5.6.11. btree_gc_coalesce in drivers/md/bcache/btree.c has a deadlock if a coalescing operation fails.

An issue was discovered in the Linux kernel through 5.6.11. sg_write lacks an sg_remove_request call in a certain failure case, aka CID-83c6f2390040.

An issue was discovered in the Linux kernel before 5.4.17. drivers/spi/spi-dw.c allows attackers to cause a panic via concurrent calls to dw_spi_irq and dw_spi_transfer_one, aka CID-19b61392c5a8.

** DISPUTED ** An issue was discovered in the Linux kernel before 5.6. svm_cpu_uninit in arch/x86/kvm/svm.c has a memory leak, aka CID-d80b64ff297e. NOTE: third parties dispute this issue because it's a one-time leak at the boot, the size is negligible, and it can't be triggered at will.

An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace, and mount a FUSE filesystem. Upon interaction with this FUSE filesystem, if the userspace component is terminated via a kill of the PID namespace's pid 1, it will result in a hung task, and resources being permanently locked up until system reboot. This can result in resource exhaustion.

There is a use-after-free in kernel versions before 5.5 due to a race condition between the release of ptp_clock and cdev while resource deallocation. When a (high privileged) process allocates a ptp device file (like /dev/ptpX) and voluntarily goes to sleep. During this time if the underlying device is removed, it can cause an exploitable condition as the process wakes up to terminate and clean all attached files. The system crashes due to the cdev structure being invalid (as already freed) which is pointed to by the inode.

An issue was discovered in the Linux kernel before 5.6.7. xdp_umem_reg in net/xdp/xdp_umem.c has an out-of-bounds write (by a user with the CAP_NET_ADMIN capability) because of a lack of headroom validation.

An issue was discovered in the Linux kernel before 5.6.5. There is a use-after-free in block/bfq-iosched.c related to bfq_idle_slice_timer_body.