Linux vulnerabilities

net/netfilter/nfnetlink_cthelper.c in the Linux kernel through 4.14.4 does not require the CAP_NET_ADMIN capability for new, get, and del operations, which allows local users to bypass intended access restrictions because the nfnl_cthelper_list data structure is shared across all net namespaces.

The bnep_add_connection function in net/bluetooth/bnep/core.c in the Linux kernel before 3.19 does not ensure that an l2cap socket is available, which allows local users to gain privileges via a crafted application.

The dccp_disconnect function in net/dccp/proto.c in the Linux kernel through 4.14.3 allows local users to gain privileges or cause a denial of service (use-after-free) via an AF_UNSPEC connect system call during the DCCP_LISTEN state.

The Linux Kernel versions 2.6.38 through 4.14 have a problematic use of pmd_mkdirty() in the touch_pmd() function inside the THP implementation. touch_pmd() can be reached by get_user_pages(). In such case, the pmd will become dirty. This scenario breaks the new can_follow_write_pmd()'s logic - pmd can become dirty without going through a COW cycle. This bug is not as severe as the original "Dirty cow" because an ext4 file (or any other regular file) cannot be mapped using THP. Nevertheless, it does allow us to overwrite read-only huge pages. For example, the zero huge page and sealed shmem files can be overwritten (since their mapping can be populated using THP). Note that after the first write page-fault to the zero page, it will be replaced with a new fresh (and zeroed) thp.

The rngapi_reset function in crypto/rng.c in the Linux kernel before 4.2 allows attackers to cause a denial of service (NULL pointer dereference).

The init_new_context function in arch/x86/include/asm/mmu_context.h in the Linux kernel before 4.12.10 does not correctly handle errors from LDT table allocation when forking a new process, allowing a local attacker to achieve a use-after-free or possibly have unspecified other impact by running a specially crafted program. This vulnerability only affected kernels built with CONFIG_MODIFY_LDT_SYSCALL=y.

The mm_init function in kernel/fork.c in the Linux kernel before 4.12.10 does not clear the ->exe_file member of a new process's mm_struct, allowing a local attacker to achieve a use-after-free or possibly have unspecified other impact by running a specially crafted program.

The walk_hugetlb_range function in mm/pagewalk.c in the Linux kernel before 4.14.2 mishandles holes in hugetlb ranges, which allows local users to obtain sensitive information from uninitialized kernel memory via crafted use of the mincore() system call.

The XFRM dump policy implementation in net/xfrm/xfrm_user.c in the Linux kernel before 4.13.11 allows local users to gain privileges or cause a denial of service (use-after-free) via a crafted SO_RCVBUF setsockopt system call in conjunction with XFRM_MSG_GETPOLICY Netlink messages.

The assoc_array_insert_into_terminal_node function in lib/assoc_array.c in the Linux kernel before 4.13.11 mishandles node splitting, which allows local users to cause a denial of service (NULL pointer dereference and panic) via a crafted application, as demonstrated by the keyring key type, and key addition and link creation operations.

The bio_map_user_iov and bio_unmap_user functions in block/bio.c in the Linux kernel before 4.13.8 do unbalanced refcounting when a SCSI I/O vector has small consecutive buffers belonging to the same page. The bio_add_pc_page function merges them into one, but the page reference is never dropped. This causes a memory leak and possible system lockup (exploitable against the host OS by a guest OS user, if a SCSI disk is passed through to a virtual machine) due to an out-of-memory condition.

The sctp_do_peeloff function in net/sctp/socket.c in the Linux kernel before 4.14 does not check whether the intended netns is used in a peel-off action, which allows local users to cause a denial of service (use-after-free and system crash) or possibly have unspecified other impact via crafted system calls.

The tower_probe function in drivers/usb/misc/legousbtower.c in the Linux kernel before 4.8.1 allows local users (who are physically proximate for inserting a crafted USB device) to gain privileges by leveraging a write-what-where condition that occurs after a race condition and a NULL pointer dereference.

An elevation of privilege vulnerability exists in the NVIDIA GPU driver (gm20b_clk_throt_set_cdev_state), where an out of bound memory read is used as a function pointer could lead to code execution in the kernel.This issue is rated as high because it could allow a local malicious application to execute arbitrary code within the context of a privileged process. Product: Android. Version: N/A. Android ID: A-34705430. References: N-CVE-2017-6264.

The qmi_wwan_bind function in drivers/net/usb/qmi_wwan.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (divide-by-zero error and system crash) or possibly have unspecified other impact via a crafted USB device.

The usbnet_generic_cdc_bind function in drivers/net/usb/cdc_ether.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (divide-by-zero error and system crash) or possibly have unspecified other impact via a crafted USB device.

The dvb_frontend_free function in drivers/media/dvb-core/dvb_frontend.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (use-after-free and system crash) or possibly have unspecified other impact via a crafted USB device. NOTE: the function was later renamed __dvb_frontend_free.

drivers/net/usb/asix_devices.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted USB device.

drivers/media/usb/dvb-usb/dib0700_devices.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (BUG and system crash) or possibly have unspecified other impact via a crafted USB device.

The ims_pcu_get_cdc_union_desc function in drivers/input/misc/ims-pcu.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (ims_pcu_parse_cdc_data out-of-bounds read and system crash) or possibly have unspecified other impact via a crafted USB device.

The hdpvr_probe function in drivers/media/usb/hdpvr/hdpvr-core.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (improper error handling and system crash) or possibly have unspecified other impact via a crafted USB device.

The parse_hid_report_descriptor function in drivers/input/tablet/gtco.c in the Linux kernel before 4.13.11 allows local users to cause a denial of service (out-of-bounds read and system crash) or possibly have unspecified other impact via a crafted USB device.

The kvm_vm_ioctl_check_extension function in arch/powerpc/kvm/powerpc.c in the Linux kernel before 4.13.11 allows local users to cause a denial of service (NULL pointer dereference and system crash) via a KVM_CHECK_EXTENSION KVM_CAP_PPC_HTM ioctl call to /dev/kvm.

drivers/media/usb/dvb-usb-v2/lmedm04.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (general protection fault and system crash) or possibly have unspecified other impact via a crafted USB device, related to a missing warm-start check and incorrect attach timing (dm04_lme2510_frontend_attach versus dm04_lme2510_tuner).

The imon_probe function in drivers/media/rc/imon.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted USB device.

The cx231xx_usb_probe function in drivers/media/usb/cx231xx/cx231xx-cards.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted USB device.

The usb_get_bos_descriptor function in drivers/usb/core/config.c in the Linux kernel before 4.13.10 allows local users to cause a denial of service (out-of-bounds read and system crash) or possibly have unspecified other impact via a crafted USB device.

The cdc_parse_cdc_header function in drivers/usb/core/message.c in the Linux kernel before 4.13.6 allows local users to cause a denial of service (out-of-bounds read and system crash) or possibly have unspecified other impact via a crafted USB device.

The usbhid_parse function in drivers/hid/usbhid/hid-core.c in the Linux kernel before 4.13.8 allows local users to cause a denial of service (out-of-bounds read and system crash) or possibly have unspecified other impact via a crafted USB device.

The get_endpoints function in drivers/usb/misc/usbtest.c in the Linux kernel through 4.13.11 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted USB device.

drivers/usb/core/config.c in the Linux kernel before 4.13.6 allows local users to cause a denial of service (out-of-bounds read and system crash) or possibly have unspecified other impact via a crafted USB device, related to the USB_DT_INTERFACE_ASSOCIATION descriptor.

The uas driver in the Linux kernel before 4.13.6 allows local users to cause a denial of service (out-of-bounds read and system crash) or possibly have unspecified other impact via a crafted USB device, related to drivers/usb/storage/uas-detect.h and drivers/usb/storage/uas.c.

The snd_usb_create_streams function in sound/usb/card.c in the Linux kernel before 4.13.6 allows local users to cause a denial of service (out-of-bounds read and system crash) or possibly have unspecified other impact via a crafted USB device.

sound/core/seq_device.c in the Linux kernel before 4.13.4 allows local users to cause a denial of service (snd_rawmidi_dev_seq_free use-after-free and system crash) or possibly have unspecified other impact via a crafted USB device.

sound/usb/mixer.c in the Linux kernel before 4.13.8 allows local users to cause a denial of service (snd_usb_mixer_interrupt use-after-free and system crash) or possibly have unspecified other impact via a crafted USB device.

drivers/uwb/uwbd.c in the Linux kernel before 4.13.6 allows local users to cause a denial of service (general protection fault and system crash) or possibly have unspecified other impact via a crafted USB device.

The usb_serial_console_disconnect function in drivers/usb/serial/console.c in the Linux kernel before 4.13.8 allows local users to cause a denial of service (use-after-free and system crash) or possibly have unspecified other impact via a crafted USB device, related to disconnection and failed setup.

On Linux running on PowerPC hardware (Power8 or later) a user process can craft a signal frame and then do a sigreturn so that the kernel will take an exception (interrupt), and use the r1 value *from the signal frame* as the kernel stack pointer. As part of the exception entry the content of the signal frame is written to the kernel stack, allowing an attacker to overwrite arbitrary locations with arbitrary values. The exception handling does produce an oops, and a panic if panic_on_oops=1, but only after kernel memory has been over written. This flaw was introduced in commit: "5d176f751ee3 (powerpc: tm: Enable transactional memory (TM) lazily for userspace)" which was merged upstream into v4.9-rc1. Please note that kernels built with CONFIG_PPC_TRANSACTIONAL_MEM=n are not vulnerable.

The altivec_unavailable_exception function in arch/powerpc/kernel/traps.c in the Linux kernel before 2.6.19 on 64-bit systems mishandles the case where CONFIG_ALTIVEC is defined and the CPU actually supports Altivec, but the Altivec support was not detected by the kernel, which allows local users to cause a denial of service (panic) by triggering execution of an Altivec instruction.

The KEYS subsystem in the Linux kernel before 4.13.10 does not correctly synchronize the actions of updating versus finding a key in the "negative" state to avoid a race condition, which allows local users to cause a denial of service or possibly have unspecified other impact via crafted system calls.

net/packet/af_packet.c in the Linux kernel before 4.13.6 allows local users to gain privileges via crafted system calls that trigger mishandling of packet_fanout data structures, because of a race condition (involving fanout_add and packet_do_bind) that leads to a use-after-free, a different vulnerability than CVE-2017-6346.

The x86/fpu (Floating Point Unit) subsystem in the Linux kernel before 4.13.5, when a processor supports the xsave feature but not the xsaves feature, does not correctly handle attempts to set reserved bits in the xstate header via the ptrace() or rt_sigreturn() system call, allowing local users to read the FPU registers of other processes on the system, related to arch/x86/kernel/fpu/regset.c and arch/x86/kernel/fpu/signal.c.

Race condition in the ALSA subsystem in the Linux kernel before 4.13.8 allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via crafted /dev/snd/seq ioctl calls, related to sound/core/seq/seq_clientmgr.c and sound/core/seq/seq_ports.c.

The KEYS subsystem in the Linux kernel through 4.13.7 mishandles use of add_key for a key that already exists but is uninstantiated, which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted system call.

security/keys/keyctl.c in the Linux kernel before 4.11.5 does not consider the case of a NULL payload in conjunction with a nonzero length value, which allows local users to cause a denial of service (NULL pointer dereference and OOPS) via a crafted add_key or keyctl system call, a different vulnerability than CVE-2017-12192.

The keyctl_read_key function in security/keys/keyctl.c in the Key Management subcomponent in the Linux kernel before 4.13.5 does not properly consider that a key may be possessed but negatively instantiated, which allows local users to cause a denial of service (OOPS and system crash) via a crafted KEYCTL_READ operation.

arch/x86/kvm/mmu.c in the Linux kernel through 4.13.5, when nested virtualisation is used, does not properly traverse guest pagetable entries to resolve a guest virtual address, which allows L1 guest OS users to execute arbitrary code on the host OS or cause a denial of service (incorrect index during page walking, and host OS crash), aka an "MMU potential stack buffer overrun."

Linux distributions that have not patched their long-term kernels with https://git.kernel.org/linus/a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (committed on April 14, 2015). This kernel vulnerability was fixed in April 2015 by commit a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (backported to Linux 3.10.77 in May 2015), but it was not recognized as a security threat. With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE enabled, and a normal top-down address allocation strategy, load_elf_binary() will attempt to map a PIE binary into an address range immediately below mm->mmap_base. Unfortunately, load_elf_ binary() does not take account of the need to allocate sufficient space for the entire binary which means that, while the first PT_LOAD segment is mapped below mm->mmap_base, the subsequent PT_LOAD segment(s) end up being mapped above mm->mmap_base into the are that is supposed to be the "gap" between the stack and the binary.

Linux kernel: Exploitable memory corruption due to UFO to non-UFO path switch. When building a UFO packet with MSG_MORE __ip_append_data() calls ip_ufo_append_data() to append. However in between two send() calls, the append path can be switched from UFO to non-UFO one, which leads to a memory corruption. In case UFO packet lengths exceeds MTU, copy = maxfraglen - skb->len becomes negative on the non-UFO path and the branch to allocate new skb is taken. This triggers fragmentation and computation of fraggap = skb_prev->len - maxfraglen. Fraggap can exceed MTU, causing copy = datalen - transhdrlen - fraggap to become negative. Subsequently skb_copy_and_csum_bits() writes out-of-bounds. A similar issue is present in IPv6 code. The bug was introduced in e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") on Oct 18 2005.

Linux kernel: heap out-of-bounds in AF_PACKET sockets. This new issue is analogous to previously disclosed CVE-2016-8655. In both cases, a socket option that changes socket state may race with safety checks in packet_set_ring. Previously with PACKET_VERSION. This time with PACKET_RESERVE. The solution is similar: lock the socket for the update. This issue may be exploitable, we did not investigate further. As this issue affects PF_PACKET sockets, it requires CAP_NET_RAW in the process namespace. But note that with user namespaces enabled, any process can create a namespace in which it has CAP_NET_RAW.