Linux Kernel Security Vulnerabilities - 2020

CVE-2020-12465

An array overflow was discovered in mt76_add_fragment in drivers/net/wireless/mediatek/mt76/dma.c in the Linux kernel before 5.5.10, aka CID-b102f0c522cf. An oversized packet with too many rx fragments can corrupt memory of adjacent pages.

CVE-2020-12652

The __mptctl_ioctl function in drivers/message/fusion/mptctl.c in the Linux kernel before 5.4.14 allows local users to hold an incorrect lock during the ioctl operation and trigger a race condition, i.e., a "double fetch" vulnerability, aka CID-28d76df18f0a. NOTE: the vendor states "The security im...

CVE-2020-12653

An issue was found in Linux kernel before 5.5.4. The mwifiex_cmd_append_vsie_tlv() function in drivers/net/wireless/marvell/mwifiex/scan.c allows local users to gain privileges or cause a denial of service because of an incorrect memcpy and buffer overflow, aka CID-b70261a288ea.

CVE-2020-12654

An issue was found in Linux kernel before 5.5.4. mwifiex_ret_wmm_get_status() in drivers/net/wireless/marvell/mwifiex/wmm.c allows a remote AP to trigger a heap-based buffer overflow because of an incorrect memcpy, aka CID-3a9b153c5591.

CVE-2020-12655

An issue was discovered in xfs_agf_verify in fs/xfs/libxfs/xfs_alloc.c in the Linux kernel through 5.6.10. Attackers may trigger a sync of excessive duration via an XFS v5 image with crafted metadata, aka CID-d0c7feaf8767.

CVE-2020-12656

gss_mech_free in net/sunrpc/auth_gss/gss_mech_switch.c in the rpcsec_gss_krb5 implementation in the Linux kernel through 5.6.10 lacks certain domain_release calls, leading to a memory leak. Note: This was disputed with the assertion that the issue does not grant any access not already available. It...

CVE-2020-12657

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.

CVE-2020-12659

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.

CVE-2020-12768

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

CVE-2020-12769

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.

CVE-2020-12770

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.

CVE-2020-12771

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.

CVE-2020-12826

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 pro...

CVE-2020-12888

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

CVE-2020-13143

gadget_dev_desc_UDC_store in drivers/usb/gadget/configfs.c in the Linux kernel 3.16 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.

CVE-2020-13974

An issue was discovered in the Linux kernel 4.4 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.

CVE-2020-14304

A memory disclosure flaw was found in the Linux kernel's ethernet drivers, in the way it read data from the EEPROM of the device. This flaw allows a local user to read uninitialized values from the kernel memory. The highest threat from this vulnerability is to confidentiality.

CVE-2020-14305

An out-of-bounds memory write flaw was found in how the Linux kernel’s Voice Over IP H.323 connection tracking functionality handled connections on ipv6 port 1720. This flaw allows an unauthenticated remote user to crash the system, causing a denial of service. The highest threat from this vulnerab...

CVE-2020-14314

A memory out-of-bounds read flaw was found in the Linux kernel before 5.9-rc2 with the ext3/ext4 file system, in the way it accesses a directory with broken indexing. This flaw allows a local user to crash the system if the directory exists. The highest threat from this vulnerability is to system a...

CVE-2020-14331

A flaw was found in the Linux kernel’s implementation of the invert video code on VGA consoles when a local attacker attempts to resize the console, calling an ioctl VT_RESIZE, which causes an out-of-bounds write to occur. This flaw allows a local user with access to the VGA console to crash the sy...

CVE-2020-14351

A flaw was found in the Linux kernel. A use-after-free memory flaw was found in the perf subsystem allowing a local attacker with permission to monitor perf events to corrupt memory and possibly escalate privileges. The highest threat from this vulnerability is to data confidentiality and integrity...

CVE-2020-14356

A flaw null pointer dereference in the Linux kernel cgroupv2 subsystem in versions before 5.7.10 was found in the way when reboot the system. A local user could use this flaw to crash the system or escalate their privileges on the system.

CVE-2020-14381

A flaw was found in the Linux kernel’s futex implementation. This flaw allows a local attacker to corrupt system memory or escalate their privileges when creating a futex on a filesystem that is about to be unmounted. The highest threat from this vulnerability is to confidentiality, integrity, as w...

CVE-2020-14385

A flaw was found in the Linux kernel before 5.9-rc4. 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 rem...

CVE-2020-14386

A flaw was found in the Linux kernel before 5.9-rc4. Memory corruption can be exploited to gain root privileges from unprivileged processes. The highest threat from this vulnerability is to data confidentiality and integrity.

CVE-2020-14390

A flaw was found in the Linux kernel in versions before 5.9-rc6. When changing screen size, an out-of-bounds memory write can occur leading to memory corruption or a denial of service. Due to the nature of the flaw, privilege escalation cannot be fully ruled out.

CVE-2020-14416

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.

CVE-2020-15393

In the Linux kernel 4.4 through 5.7.6, usbtest_disconnect in drivers/usb/misc/usbtest.c has a memory leak, aka CID-28ebeb8db770.

CVE-2020-15436

Use-after-free vulnerability in fs/block_dev.c in the Linux kernel before 5.8 allows local users to gain privileges or cause a denial of service by leveraging improper access to a certain error field.

CVE-2020-15437

The Linux kernel before version 5.8 is vulnerable to a NULL pointer dereference in drivers/tty/serial/8250/8250_core.c:serial8250_isa_init_ports() that allows local users to cause a denial of service by using the p->serial_in pointer which uninitialized.

CVE-2020-15780

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.

CVE-2020-15852

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...

CVE-2020-16166

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.

CVE-2020-1749

A flaw was found in the Linux kernel's implementation of some networking protocols in IPsec, such as VXLAN and GENEVE tunnels over IPv6. When an encrypted tunnel is created between two hosts, the kernel isn't correctly routing tunneled data over the encrypted link; rather sending the data unencrypt...

CVE-2020-24394

In the Linux kernel before 5.7.8, fs/nfsd/vfs.c (in the NFS server) can set incorrect permissions on new filesystem objects when the filesystem lacks ACL support, aka CID-22cf8419f131. This occurs because the current umask is not considered.

CVE-2020-25211

In the Linux kernel through 5.8.7, local attackers able to inject conntrack netlink configuration could overflow a local buffer, causing crashes or triggering use of incorrect protocol numbers in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c, aka CID-1cc5ef91d2ff.

CVE-2020-25212

A TOCTOU mismatch in the NFS client code in the Linux kernel before 5.8.3 could be used by local attackers to corrupt memory or possibly have unspecified other impact because a size check is in fs/nfs/nfs4proc.c instead of fs/nfs/nfs4xdr.c, aka CID-b4487b935452.

CVE-2020-25220

The Linux kernel 4.9.x before 4.9.233, 4.14.x before 4.14.194, and 4.19.x before 4.19.140 has a use-after-free because skcd->no_refcnt was not considered during a backport of a CVE-2020-14356 patch. This is related to the cgroups feature.

CVE-2020-25221

get_gate_page in mm/gup.c in the Linux kernel 5.7.x and 5.8.x before 5.8.7 allows privilege escalation because of incorrect reference counting (caused by gate page mishandling) of the struct page that backs the vsyscall page. The result is a refcount underflow. This can be triggered by any 64-bit p...

CVE-2020-25284

The rbd block device driver in drivers/block/rbd.c in the Linux kernel through 5.8.9 used incomplete permission checking for access to rbd devices, which could be leveraged by local attackers to map or unmap rbd block devices, aka CID-f44d04e696fe.

CVE-2020-25285

A race condition between hugetlb sysctl handlers in mm/hugetlb.c in the Linux kernel before 5.8.8 could be used by local attackers to corrupt memory, cause a NULL pointer dereference, or possibly have unspecified other impact, aka CID-17743798d812.

CVE-2020-25641

A flaw was found in the Linux kernel's implementation of biovecs in versions before 5.9-rc7. A zero-length biovec request issued by the block subsystem could cause the kernel to enter an infinite loop, causing a denial of service. This flaw allows a local attacker with basic privileges to issue req...

CVE-2020-25643

A flaw was found in the HDLC_PPP module of the Linux kernel in versions before 5.9-rc7. Memory corruption and a read overflow is caused by improper input validation in the ppp_cp_parse_cr function which can cause the system to crash or cause a denial of service. The highest threat from this vulnera...

CVE-2020-25645

A flaw was found in the Linux kernel in versions before 5.9-rc7. Traffic between two Geneve endpoints may be unencrypted when IPsec is configured to encrypt traffic for the specific UDP port used by the GENEVE tunnel allowing anyone between the two endpoints to read the traffic unencrypted. The mai...

CVE-2020-25656

A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality.

CVE-2020-25704

A flaw memory leak in the Linux kernel performance monitoring subsystem was found in the way if using PERF_EVENT_IOC_SET_FILTER. A local user could use this flaw to starve the resources causing denial of service.

CVE-2020-25705

A flaw in ICMP packets in the Linux kernel may allow an attacker to quickly scan open UDP ports. This flaw allows an off-path remote attacker to effectively bypass source port UDP randomization. Software that relies on UDP source port randomization are indirectly affected as well on the Linux Based...

CVE-2020-26088

A missing CAP_NET_RAW check in NFC socket creation in net/nfc/rawsock.c in the Linux kernel before 5.8.2 could be used by local attackers to create raw sockets, bypassing security mechanisms, aka CID-26896f01467a.

CVE-2020-26541

The Linux kernel through 5.8.13 does not properly enforce the Secure Boot Forbidden Signature Database (aka dbx) protection mechanism. This affects certs/blacklist.c and certs/system_keyring.c.

CVE-2020-27152

An issue was discovered in ioapic_lazy_update_eoi in arch/x86/kvm/ioapic.c in the Linux kernel before 5.9.2. It has an infinite loop related to improper interaction between a resampler and edge triggering, aka CID-77377064c3a9.