In the Linux kernel through 5.2.1 on the powerpc platform, when hardware transactional memory is disabled, a local user can cause a denial of service (TM Bad Thing exception and system crash) via a sigreturn() system call that sends a crafted signal frame. This affects arch/powerpc/kernel/signal_32.c and arch/powerpc/kernel/signal_64.c.

In parse_hid_report_descriptor in drivers/input/tablet/gtco.c in the Linux kernel through 5.2.1, a malicious USB device can send an HID report that triggers an out-of-bounds write during generation of debugging messages.

The Linux kernel 4.x (starting from 4.1) and 5.x before 5.0.8 allows Information Exposure (partial kernel address disclosure), leading to a KASLR bypass. Specifically, it is possible to extract the KASLR kernel image offset using the IP ID values the kernel produces for connection-less protocols (e.g., UDP and ICMP). When such traffic is sent to multiple destination IP addresses, it is possible to obtain hash collisions (of indices to the counter array) and thereby obtain the hashing key (via enumeration). This key contains enough bits from a kernel address (of a static variable) so when the key is extracted (via enumeration), the offset of the kernel image is exposed. This attack can be carried out remotely, by the attacker forcing the target device to send UDP or ICMP (or certain other) traffic to attacker-controlled IP addresses. Forcing a server to send UDP traffic is trivial if the server is a DNS server. ICMP traffic is trivial if the server answers ICMP Echo requests (ping). For client targets, if the target visits the attacker's web page, then WebRTC or gQUIC can be used to force UDP traffic to attacker-controlled IP addresses. NOTE: this attack against KASLR became viable in 4.1 because IP ID generation was changed to have a dependency on an address associated with a network namespace.

In the Linux kernel before 5.1.7, a device can be tracked by an attacker using the IP ID values the kernel produces for connection-less protocols (e.g., UDP and ICMP). When such traffic is sent to multiple destination IP addresses, it is possible to obtain hash collisions (of indices to the counter array) and thereby obtain the hashing key (via enumeration). An attack may be conducted by hosting a crafted web page that uses WebRTC or gQUIC to force UDP traffic to attacker-controlled IP addresses.

In arch/x86/lib/insn-eval.c in the Linux kernel before 5.1.9, there is a use-after-free for access to an LDT entry because of a race condition between modify_ldt() and a #BR exception for an MPX bounds violation.

A NULL pointer dereference vulnerability in the function nfc_genl_deactivate_target() in net/nfc/netlink.c in the Linux kernel before 5.1.13 can be triggered by a malicious user-mode program that omits certain NFC attributes, leading to denial of service.

arch/powerpc/mm/mmu_context_book3s64.c in the Linux kernel before 5.1.15 for powerpc has a bug where unrelated processes may be able to read/write to one another's virtual memory under certain conditions via an mmap above 512 TB. Only a subset of powerpc systems are affected.

An issue was discovered in the Linux kernel before 5.0. The function __mdiobus_register() in drivers/net/phy/mdio_bus.c calls put_device(), which will trigger a fixed_mdio_bus_init use-after-free. This will cause a denial of service.

An issue was discovered in the Linux kernel before 4.20.15. The nfc_llcp_build_tlv function in net/nfc/llcp_commands.c may return NULL. If the caller does not check for this, it will trigger a NULL pointer dereference. This will cause denial of service. This affects nfc_llcp_build_gb in net/nfc/llcp_core.c.

An issue was discovered in dlpar_parse_cc_property in arch/powerpc/platforms/pseries/dlpar.c in the Linux kernel through 5.1.6. There is an unchecked kstrdup of prop->name, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash).

An issue was discovered in the MPT3COMMAND case in _ctl_ioctl_main in drivers/scsi/mpt3sas/mpt3sas_ctl.c in the Linux kernel through 5.1.5. It allows local users to cause a denial of service or possibly have unspecified other impact by changing the value of ioc_number between two kernel reads of that value, aka a "double fetch" vulnerability. NOTE: a third party reports that this is unexploitable because the doubly fetched value is not used

An issue was discovered in sunxi_divs_clk_setup in drivers/clk/sunxi/clk-sunxi.c in the Linux kernel through 5.1.5. There is an unchecked kstrndup of derived_name, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash). NOTE: This id is disputed as not being an issue because “The memory allocation that was not checked is part of a code that only runs at boot time, before user processes are started. Therefore, there is no possibility for an unprivileged user to control it, and no denial of service.”

An issue was discovered in wcd9335_codec_enable_dec in sound/soc/codecs/wcd9335.c in the Linux kernel through 5.1.5. It uses kstrndup instead of kmemdup_nul, which allows attackers to have an unspecified impact via unknown vectors. NOTE: The vendor disputes this issues as not being a vulnerability because switching to kmemdup_nul() would only fix a security issue if the source string wasn't NUL-terminated, which is not the case

An issue was discovered in drm_load_edid_firmware in drivers/gpu/drm/drm_edid_load.c in the Linux kernel through 5.1.5. There is an unchecked kstrdup of fwstr, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash). NOTE: The vendor disputes this issues as not being a vulnerability because kstrdup() returning NULL is handled sufficiently and there is no chance for a NULL pointer dereference

An issue was discovered in ip_ra_control in net/ipv4/ip_sockglue.c in the Linux kernel through 5.1.5. There is an unchecked kmalloc of new_ra, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash). NOTE: this is disputed because new_ra is never used if it is NULL

**DISPUTED** An issue was discovered in the efi subsystem in the Linux kernel through 5.1.5. phys_efi_set_virtual_address_map in arch/x86/platform/efi/efi.c and efi_call_phys_prolog in arch/x86/platform/efi/efi_64.c mishandle memory allocation failures. NOTE: This id is disputed as not being an issue because “All the code touched by the referenced commit runs only at boot, before any user processes are started. Therefore, there is no possibility for an unprivileged user to control it.”.

An issue was discovered in con_insert_unipair in drivers/tty/vt/consolemap.c in the Linux kernel through 5.1.5. There is a memory leak in a certain case of an ENOMEM outcome of kmalloc. NOTE: This id is disputed as not being an issue

An issue was discovered in ip6_ra_control in net/ipv6/ipv6_sockglue.c in the Linux kernel through 5.1.5. There is an unchecked kmalloc of new_ra, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash). NOTE: This has been disputed as not an issue

fs/ext4/extents.c in the Linux kernel through 5.1.2 does not zero out the unused memory region in the extent tree block, which might allow local users to obtain sensitive information by reading uninitialized data in the filesystem.

The do_hidp_sock_ioctl function in net/bluetooth/hidp/sock.c in the Linux kernel before 5.0.15 allows a local user to obtain potentially sensitive information from kernel stack memory via a HIDPCONNADD command, because a name field may not end with a '\0' character.