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 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.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: use after free in the video driver leads to local privilege escalation (CVE-2019-9458)

• kernel: use-after-free in drivers/bluetooth/hci_ldisc.c (CVE-2019-15917)

• kernel: out-of-bounds access in function hclge_tm_schd_mode_vnet_base_cfg (CVE-2019-15925)

• kernel: memory leak in ccp_run_sha_cmd() (CVE-2019-18808)

• kernel: Denial Of Service in the __ipmi_bmc_register() (CVE-2019-19046)

• kernel: out-of-bounds write in ext4_xattr_set_entry (CVE-2019-19319)

• Kernel: kvm: OOB memory write via kvm_dev_ioctl_get_cpuid (CVE-2019-19332)

• kernel: use-after-free in ext4_put_super (CVE-2019-19447)

• kernel: a malicious USB device in the drivers/input/ff-memless.c leads to use-after-free (CVE-2019-19524)

• kernel: race condition caused by a malicious USB device in the USB character device driver layer (CVE-2019-19537)

• kernel: use-after-free in serial_ir_init_module() (CVE-2019-19543)

• kernel: use-after-free in __ext4_expand_extra_isize and ext4_xattr_set_entry (CVE-2019-19767)

• kernel: use-after-free in debugfs_remove (CVE-2019-19770)

• kernel: out-of-bounds write via crafted keycode table (CVE-2019-20636)

• kernel: possible use-after-free due to a race condition in cdev_get (CVE-2020-0305)

• kernel: out-of-bounds read in in vc_do_resize function (CVE-2020-8647)

• kernel: use-after-free in n_tty_receive_buf_common function (CVE-2020-8648)

• kernel: invalid read location in vgacon_invert_region function (CVE-2020-8649)

• kernel: uninitialized kernel data leak in userspace coredumps (CVE-2020-10732)

• kernel: SELinux netlink permission check bypass (CVE-2020-10751)

• kernel: out-of-bounds write in mpol_parse_str (CVE-2020-11565)

• kernel: mishandles invalid descriptors in drivers/media/usb/gspca/xirlink_cit.c (CVE-2020-11668)

• kernel: buffer overflow in mt76_add_fragment function (CVE-2020-12465)

• kernel: xdp_umem_reg in net/xdp/xdp_umem.c has an out-of-bounds write which could result in crash and data coruption (CVE-2020-12659)

• kernel: sg_write function lacks an sg_remove_request call in a certain failure case (CVE-2020-12770)

• kernel: possible to send arbitrary signals to a privileged (suidroot) parent process (CVE-2020-12826)

• kernel: referencing inode of removed superblock in get_futex_key() causes UAF (CVE-2020-14381)

• kernel: soft-lockups in iov_iter_copy_from_user_atomic() could result in DoS (CVE-2020-25641)

• kernel: kernel pointer leak due to WARN_ON statement in video driver leads to local information disclosure (CVE-2019-9455)

• kernel: null pointer dereference in dlpar_parse_cc_property (CVE-2019-12614)

• kernel: null-pointer dereference in drivers/net/fjes/fjes_main.c (CVE-2019-16231)

• kernel: null pointer dereference in drivers/scsi/qla2xxx/qla_os.c (CVE-2019-16233)

• kernel: memory leak in af9005_identify_state() function (CVE-2019-18809)

• kernel: A memory leak in the mwifiex_pcie_alloc_cmdrsp_buf() function (CVE-2019-19056)

• kernel: memory leak in the crypto_report() function (CVE-2019-19062)

• kernel: Two memory leaks in the rtl_usb_probe() function (CVE-2019-19063)

• kernel: A memory leak in the rtl8xxxu_submit_int_urb() function (CVE-2019-19068)

• kernel: A memory leak in the predicate_parse() function (CVE-2019-19072)

• kernel: information leak bug caused by a malicious USB device in the drivers/media/usb/ttusb-dec/ttusb_dec.c (CVE-2019-19533)

• kernel: Null pointer dereference in drop_sysctl_table() (CVE-2019-20054)

• kernel: kernel stack information leak on s390/s390x (CVE-2020-10773)

• kernel: possibility of memory disclosure when reading the file /proc/sys/kernel/rh_features (CVE-2020-10774)

• kernel: vhost-net: stack overflow in get_raw_socket while checking sk_family field (CVE-2020-10942)

• kernel: sync of excessive duration via an XFS v5 image with crafted metadata (CVE-2020-12655)

It was discovered that the btrfs implementation in the Linux kernel did not properly detect that a block was marked dirty in some situations. An attacker could use this to specially craft a file system image that, when unmounted, could cause a denial of service (system crash). (CVE-2019-19377)

It was discovered that the linux kernel did not properly validate certain mount options to the tmpfs virtual memory file system. A local attacker with the ability to specify mount options could use this to cause a denial of service (system crash). (CVE-2020-11565)

It was discovered that the block layer in the Linux kernel contained a race condition leading to a use-after-free vulnerability. A local attacker could possibly use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2020-12657)

It was discovered that the btrfs implementation in the Linux kernel did not properly detect that a block was marked dirty in some situations. An attacker could use this to specially craft a file system image that, when unmounted, could cause a denial of service (system crash). (CVE-2019-19377)

Tristan Madani discovered that the file locking implementation in the Linux kernel contained a race condition. A local attacker could possibly use this to cause a denial of service or expose sensitive information. (CVE-2019-19769)

It was discovered that the Serial CAN interface driver in the Linux kernel did not properly initialize data. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-11494)

It was discovered that the linux kernel did not properly validate certain mount options to the tmpfs virtual memory file system. A local attacker with the ability to specify mount options could use this to cause a denial of service (system crash). (CVE-2020-11565)

It was discovered that the OV51x USB Camera device driver in the Linux kernel did not properly validate device metadata. A physically proximate attacker could use this to cause a denial of service (system crash). (CVE-2020-11608)

It was discovered that the STV06XX USB Camera device driver in the Linux kernel did not properly validate device metadata. A physically proximate attacker could use this to cause a denial of service (system crash). (CVE-2020-11609)

It was discovered that the Xirlink C-It USB Camera device driver in the Linux kernel did not properly validate device metadata. A physically proximate attacker could use this to cause a denial of service (system crash). (CVE-2020-11668)

It was discovered that the block layer in the Linux kernel contained a race condition leading to a use-after-free vulnerability. A local attacker could possibly use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2020-12657)

It was discovered that the ext4 file system implementation in the Linux kernel did not properly handle setxattr operations in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-19319)

It was discovered that memory contents previously stored in microarchitectural special registers after RDRAND, RDSEED, and SGX EGETKEY read operations on Intel client and Xeon E3 processors may be briefly exposed to processes on the same or different processor cores. A local attacker could use this to expose sensitive information. (CVE-2020-0543)

Piotr Krysiuk discovered that race conditions existed in the file system implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-12114)

It was discovered that the USB susbsystem's scatter-gather implementation in the Linux kernel did not properly take data references in some situations, leading to a use-after-free. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-12464)

It was discovered that the DesignWare SPI controller driver in the Linux kernel contained a race condition. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2020-12769)

It was discovered that the exit signaling implementation in the Linux kernel contained an integer overflow. A local attacker could use this to cause a denial of service (arbitrary application crash). (CVE-2020-12826)

Xiumei Mu discovered that the IPSec implementation in the Linux kernel did not properly encrypt IPv6 traffic in some situations. An attacker could use this to expose sensitive information. (CVE-2020-1749)

Dmitry Vyukov discovered that the SELinux netlink security hook in the Linux kernel did not validate messages in some situations. A privileged attacker could use this to bypass SELinux netlink restrictions. (CVE-2020-10751)