The get_instantiation_keyring function in security/keys/keyctl.c in the KEYS subsystem in the Linux kernel before 2.6.32-rc5 does not properly maintain the reference count of a keyring, which allows local users to gain privileges or cause a denial of service (OOPS) via vectors involving calls to this function without specifying a keyring by ID, as demonstrated by a series of keyctl request2 and keyctl list commands.

The lookup_cb_cred function in fs/nfsd/nfs4callback.c in the nfsd4 subsystem in the Linux kernel before 2.6.31.2 attempts to access a credentials cache even when a client specifies the AUTH_NULL authentication flavor, which allows remote attackers to cause a denial of service (NULL pointer dereference and system crash) via an NFSv4 mount request.

The handle_dr function in arch/x86/kvm/vmx.c in the KVM subsystem in the Linux kernel before 2.6.31.1 does not properly verify the Current Privilege Level (CPL) before accessing a debug register, which allows guest OS users to cause a denial of service (trap) on the host OS via a crafted application.

Integer overflow in the kvm_dev_ioctl_get_supported_cpuid function in arch/x86/kvm/x86.c in the KVM subsystem in the Linux kernel before 2.6.31.4 allows local users to have an unspecified impact via a KVM_GET_SUPPORTED_CPUID request to the kvm_arch_dev_ioctl function.

The update_cr8_intercept function in arch/x86/kvm/x86.c in the KVM subsystem in the Linux kernel before 2.6.32-rc1 does not properly handle the absence of an Advanced Programmable Interrupt Controller (APIC), which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly gain privileges via a call to the kvm_vcpu_ioctl function.

Integer signedness error in the ax25_setsockopt function in net/ax25/af_ax25.c in the ax25 subsystem in the Linux kernel before 2.6.31.2 allows local users to cause a denial of service (OOPS) via a crafted optlen value in an SO_BINDTODEVICE operation.

The tty_ldisc_hangup function in drivers/char/tty_ldisc.c in the Linux kernel 2.6.31-rc before 2.6.31-rc8 allows local users to cause a denial of service (system crash, sometimes preceded by a NULL pointer dereference) or possibly gain privileges via certain pseudo-terminal I/O activity, as demonstrated by KernelTtyTest.c.

The Linux kernel before 2.6.31-rc7 does not properly prevent mmap operations that target page zero and other low memory addresses, which allows local users to gain privileges by exploiting NULL pointer dereference vulnerabilities, related to (1) the default configuration of the allow_unconfined_mmap_low boolean in SELinux on Red Hat Enterprise Linux (RHEL) 5, (2) an error that causes allow_unconfined_mmap_low to be ignored in the unconfined_t domain, (3) lack of a requirement for the CAP_SYS_RAWIO capability for these mmap operations, and (4) interaction between the mmap_min_addr protection mechanism and certain application programs.

The md driver (drivers/md/md.c) in the Linux kernel before 2.6.30.2 might allow local users to cause a denial of service (NULL pointer dereference) via vectors related to "suspend_* sysfs attributes" and the (1) suspend_lo_store or (2) suspend_hi_store functions. NOTE: this is only a vulnerability when sysfs is writable by an attacker.

The execve function in the Linux kernel, possibly 2.6.30-rc6 and earlier, does not properly clear the current->clear_child_tid pointer, which allows local users to cause a denial of service (memory corruption) or possibly gain privileges via a clone system call with CLONE_CHILD_SETTID or CLONE_CHILD_CLEARTID enabled, which is not properly handled during thread creation and exit.