In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init() l2cap_le_flowctl_init() can cause both div-by-zero and an integer overflow since hdev->le_mtu may not fall in the valid range. Move MTU from hci_dev to hci_conn to validate MTU and stop the connection process earlier if MTU is invalid. Also, add a missing validation in read_buffer_size() and make it return an error value if the validation fails. Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a kzalloc failure and invalid MTU value. divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 worker_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]---

The ldm_parse_vmdb function in fs/partitions/ldm.c in the Linux kernel before 2.6.38-rc6-git6 does not validate the VBLK size value in the VMDB structure in an LDM partition table, which allows local users to cause a denial of service (divide-by-zero error and OOPS) via a crafted partition table.

The tcp_disconnect function in net/ipv4/tcp.c in the Linux kernel before 4.12 allows local users to cause a denial of service (__tcp_select_window divide-by-zero error and system crash) by triggering a disconnect within a certain tcp_recvmsg code path.

Quick emulator (Qemu) built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to a divide by zero issue. It could occur while copying VGA data when cirrus graphics mode was set to be VGA. A privileged user inside guest could use this flaw to crash the Qemu process instance on the host, resulting in DoS.

In ImfChromaticities.cpp routine RGBtoXYZ(), there are some division operations such as `float Z = (1 - chroma.white.x - chroma.white.y) * Y / chroma.white.y;` and `chroma.green.y * (X + Z))) / d;` but the divisor is not checked for a 0 value. A specially crafted file could trigger a divide-by-zero condition which could affect the availability of programs linked with OpenEXR.

The Virtio Vring implementation in QEMU allows local OS guest users to cause a denial of service (divide-by-zero error and QEMU process crash) by unsetting vring alignment while updating Virtio rings.

The do_tcp_setsockopt function in net/ipv4/tcp.c in the Linux kernel before 2.6.37-rc2 does not properly restrict TCP_MAXSEG (aka MSS) values, which allows local users to cause a denial of service (OOPS) via a setsockopt call that specifies a small value, leading to a divide-by-zero error or incorrect use of a signed integer.

In change_port_settings in drivers/usb/serial/io_ti.c in the Linux kernel before 4.11.3, local users could cause a denial of service by division-by-zero in the serial device layer by trying to set very high baud rates.

The Universal Disk Format (UDF) filesystem driver in Linux kernel 2.6.17 and earlier allows local users to cause a denial of service (hang and crash) via certain operations involving truncated files, as demonstrated via the dd command.

The perfmonctl system call (sys_perfmonctl) in Linux kernel 2.4.x and 2.6 before 2.6.18, when running on Itanium systems, does not properly track the reference count for file descriptors, which allows local users to cause a denial of service (file descriptor consumption).

An issue was discovered in the Linux kernel through 5.11.3, as used with Xen PV. A certain part of the netback driver lacks necessary treatment of errors such as failed memory allocations (as a result of changes to the handling of grant mapping errors). A host OS denial of service may occur during misbehavior of a networking frontend driver. NOTE: this issue exists because of an incomplete fix for CVE-2021-26931.

Stack-based buffer overflow in the megasas_ctrl_get_info function in QEMU, when built with SCSI MegaRAID SAS HBA emulation support, allows local guest users to cause a denial of service (QEMU instance crash) via a crafted SCSI controller CTRL_GET_INFO command.

The ehci_process_itd function in hw/usb/hcd-ehci.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) via a circular isochronous transfer descriptor (iTD) list.

The ia64 subsystem in the Linux kernel before 2.6.26 allows local users to cause a denial of service (stack consumption and system crash) via a crafted application that leverages the mishandling of invalid Register Stack Engine (RSE) state.

net/sctp/sm_sideeffect.c in the Linux kernel before 4.3 does not properly manage the relationship between a lock and a socket, which allows local users to cause a denial of service (deadlock) via a crafted sctp_accept call.

Linux kernel 2.x.6 before 2.6.17.9 and 2.4.x before 2.4.33.1 on PowerPC PPC970 systems allows local users to cause a denial of service (crash) related to the "HID0 attention enable on PPC970 at boot time."

The eepro100 emulator in QEMU qemu-kvm blank allows local guest users to cause a denial of service (application crash and infinite loop) via vectors involving the command block list.

A regression error in the restore_all code path of the 4/4GB split support for non-hugemem Linux kernels on Red Hat Linux Desktop and Enterprise Linux 4 allows local users to cause a denial of service (panic) via unspecified vectors.

crypto/algif_skcipher.c in the Linux kernel before 4.4.2 does not verify that a setkey operation has been performed on an AF_ALG socket before an accept system call is processed, which allows local users to cause a denial of service (NULL pointer dereference and system crash) via a crafted application that does not supply a key, related to the lrw_crypt function in crypto/lrw.c.

The sys_add_key function in the keyring code in Linux kernel 2.6.16.1 and 2.6.17-rc1, and possibly earlier versions, allows local users to cause a denial of service (OOPS) via keyctl requests that add a key to a user key instead of a keyring key, which causes an invalid dereference in the __keyring_search_one function.

Linux kernel before 2.6.13 allows local users to cause a denial of service (crash) via a dio transfer from the sg driver to memory mapped (mmap) IO space.

fs/overlayfs/copy_up.c in the Linux kernel before 4.2.6 uses an incorrect cleanup code path, which allows local users to cause a denial of service (dentry reference leak) via filesystem operations on a large file in a lower overlayfs layer.

ip_route_input in Linux kernel 2.6 before 2.6.16.8 allows local users to cause a denial of service (panic) via a request for a route for a multicast IP address, which triggers a null dereference.

net/ipv6/tcp_ipv6.c in Linux kernel 2.6.x up to 2.6.21-rc3 inadvertently copies the ipv6_fl_socklist from a listening TCP socket to child sockets, which allows local users to cause a denial of service (OOPS) or double free by opening a listening IPv6 socket, attaching a flow label, and connecting to that socket.

The fuse_fill_write_pages function in fs/fuse/file.c in the Linux kernel before 4.4 allows local users to cause a denial of service (infinite loop) via a writev system call that triggers a zero length for the first segment of an iov.

Linux kernel before 2.6.16.5 does not properly handle uncanonical return addresses on Intel EM64T CPUs, which reports an exception in the SYSRET instead of the next instruction, which causes the kernel exception handler to run on the user stack with the wrong GS.

The fill_write_buffer function in sysfs/file.c in Linux kernel 2.6.12 up to versions before 2.6.17-rc1 does not zero terminate a buffer when a length of PAGE_SIZE or more is requested, which might allow local users to cause a denial of service (crash) by causing an out-of-bounds read.

The ext3fs_dirhash function in Linux kernel 2.6.x allows local users to cause a denial of service (crash) via an ext3 stream with malformed data structures.

An issue was discovered in the Linux kernel before 5.0.9. There is a NULL pointer dereference for a cd data structure if alloc_disk fails in drivers/block/paride/pf.c.

Improper authorization vulnerability in Tizen factory reset policy prior to Firmware update JUL-2021 Release allows untrusted applications to perform factory reset using dbus signal.

The hugepage code (hugetlb.c) in Linux kernel 2.6, possibly 2.6.12 and 2.6.13, in certain configurations, allows local users to cause a denial of service (crash) by triggering an mmap error before a prefault, which causes an error in the unmap_hugepage_area function.

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Bury Intel PT virtualization (guest/host mode) behind CONFIG_BROKEN Hide KVM's pt_mode module param behind CONFIG_BROKEN, i.e. disable support for virtualizing Intel PT via guest/host mode unless BROKEN=y. There are myriad bugs in the implementation, some of which are fatal to the guest, and others which put the stability and health of the host at risk. For guest fatalities, the most glaring issue is that KVM fails to ensure tracing is disabled, and *stays* disabled prior to VM-Enter, which is necessary as hardware disallows loading (the guest's) RTIT_CTL if tracing is enabled (enforced via a VMX consistency check). Per the SDM: If the logical processor is operating with Intel PT enabled (if IA32_RTIT_CTL.TraceEn = 1) at the time of VM entry, the "load IA32_RTIT_CTL" VM-entry control must be 0. On the host side, KVM doesn't validate the guest CPUID configuration provided by userspace, and even worse, uses the guest configuration to decide what MSRs to save/load at VM-Enter and VM-Exit. E.g. configuring guest CPUID to enumerate more address ranges than are supported in hardware will result in KVM trying to passthrough, save, and load non-existent MSRs, which generates a variety of WARNs, ToPA ERRORs in the host, a potential deadlock, etc.

The netlink_rcv_skb function in af_netlink.c in Linux kernel 2.6.14 and 2.6.15 allows local users to cause a denial of service (infinite loop) via a nlmsg_len field of 0.

ip_nat_pptp in the PPTP NAT helper (netfilter/ip_nat_helper_pptp.c) in Linux kernel 2.6.14, and other versions, allows local users to cause a denial of service (memory corruption or crash) via a crafted outbound packet that causes an incorrect offset to be calculated from pointer arithmetic when non-linear SKBs (socket buffers) are used.

Memory leak in QEMU, when built with a VMWARE VMXNET3 paravirtual NIC emulator support, allows local guest users to cause a denial of service (host memory consumption) by trying to activate the vmxnet3 device repeatedly.

The ext4 implementation in the Linux kernel before 2.6.34 does not properly track the initialization of certain data structures, which allows physically proximate attackers to cause a denial of service (NULL pointer dereference and panic) via a crafted USB device, related to the ext4_fill_super function.

The keyctl_read_key function in security/keys/keyctl.c in the Linux kernel before 4.3.4 does not properly use a semaphore, 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 application that leverages a race condition between keyctl_revoke and keyctl_read calls.

The time_out_leases function in locks.c for Linux kernel before 2.6.15-rc3 allows local users to cause a denial of service (kernel log message consumption) by causing a large number of broken leases, which is recorded to the log using the printk function.

The atm module in Linux kernel 2.6 before 2.6.14 allows local users to cause a denial of service (panic) via certain socket calls that produce inconsistent reference counts for loadable protocol modules.

The auto-reap of child processes in Linux kernel 2.6 before 2.6.15 includes processes with ptrace attached, which leads to a dangling ptrace reference and allows local users to cause a denial of service (crash) and gain root privileges.

A locking problem in POSIX timer cleanup handling on exit in Linux kernel 2.6.10 to 2.6.14, when running on SMP systems, allows local users to cause a denial of service (deadlock) involving process CPU timers.

Linux kernel before 2.6.15 allows local users to cause a denial of service (panic) via a set_mempolicy call with a 0 bitmask, which causes a panic when a page fault occurs.

Memory leak in the VFS file lease handling in locks.c in Linux kernels 2.6.10 to 2.6.15 allows local users to cause a denial of service (memory exhaustion) via certain Samba activities that cause an fasync entry to be re-allocated by the fcntl_setlease function after the fasync queue has already been cleaned by the locks_delete_lock function.

The I/O implementation for block devices in the Linux kernel before 2.6.33 does not properly handle the CLONE_IO feature, which allows local users to cause a denial of service (I/O instability) by starting multiple processes that share an I/O context.