The Linux kernel before 2.6.16.9 and the FreeBSD kernel, when running on AMD64 and other 7th and 8th generation AuthenticAMD processors, only save/restore the FOP, FIP, and FDP x87 registers in FXSAVE/FXRSTOR when an exception is pending, which allows one process to determine portions of the state of floating point instructions of other processes, which can be leveraged to obtain sensitive information such as cryptographic keys. NOTE: this is the documented behavior of AMD64 processors, but it is inconsistent with Intel processors in a security-relevant fashion that was not addressed by the kernels.

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.

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.

perfmon (perfmon.c) in Linux kernel on IA64 architectures allows local users to cause a denial of service (crash) by interrupting a task while another process is accessing the mm_struct, which triggers a BUG_ON action in the put_page_testzero function.

Linux kernel 2.6.16-rc2 and earlier, when running on x86_64 systems with preemption enabled, allows local users to cause a denial of service (oops) via multiple ptrace tasks that perform single steps, which can cause corruption of the DEBUG_STACK stack during the do_debug function call.

Integer overflow in the do_replace function in netfilter for Linux before 2.6.16-rc3, when using "virtualization solutions" such as OpenVZ, allows local users with CAP_NET_ADMIN rights to cause a buffer overflow in the copy_from_user function.

The ip_push_pending_frames function in Linux 2.4.x and 2.6.x before 2.6.16 increments the IP ID field when sending a RST after receiving unsolicited TCP SYN-ACK packets, which allows remote attackers to conduct an Idle Scan (nmap -sI) attack, which bypasses intended protections against such attacks.

Race condition in the (1) add_key, (2) request_key, and (3) keyctl functions in Linux kernel 2.6.x allows local users to cause a denial of service (crash) or read sensitive kernel memory by modifying the length of a string argument between the time that the kernel calculates the length and when it copies the data into kernel memory.

sys_mbind in mempolicy.c in Linux kernel 2.6.16 and earlier does not sanity check the maxnod variable before making certain computations for the get_nodes function, which has unknown impact and attack vectors.

The die_if_kernel function in arch/ia64/kernel/unaligned.c in Linux kernel 2.6.x before 2.6.15.6, possibly when compiled with certain versions of gcc, has the "noreturn" attribute set, which allows local users to cause a denial of service by causing user faults on Itanium systems.

Linux kernel 2.6 before 2.6.15.5 allows local users to obtain sensitive information via a crafted XFS ftruncate call, which may return stale data.

The Linux Kernel before 2.6.15.5 allows local users to cause a denial of service (NFS client panic) via unknown attack vectors related to the use of O_DIRECT (direct I/O).

Linux kernel before 2.6.15.5, when running on Intel processors, allows local users to cause a denial of service ("endless recursive fault") via unknown attack vectors related to a "bad elf entry address."

Linux kernel 2.6.15.1 and earlier, when running on SPARC architectures, allows local users to cause a denial of service (hang) via a "date -s" command, which causes invalid sign extended arguments to be provided to the get_compat_timespec function call.

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 securelevels implementation in NetBSD 2.1 and earlier, and Linux 2.6.15 and earlier, allows local users to bypass time setting restrictions and set the clock backwards by setting the clock ahead to the maximum unixtime value (19 Jan 2038), which then wraps around to the minimum value (13 Dec 1901), which can then be set ahead to the desired time, aka "settimeofday() time wrap."

Buffer overflow in sysctl in the Linux Kernel 2.6 before 2.6.15 allows local users to corrupt user memory and possibly cause a denial of service via a long string, which causes sysctl to write a zero byte outside the buffer. NOTE: since the sysctl is called from a userland program that provides the argument, this might not be a vulnerability, unless a legitimate user-assisted or setuid scenario can be identified.

The nl_fib_input function in fib_frontend.c in the Linux kernel before 2.6.15 does not check for valid lengths of the header and payload, which allows remote attackers to cause a denial of service (invalid memory reference) via malformed fib_lookup netlink messages.

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.

Linux kernel 2.4 and 2.6 allows attackers to cause a denial of service (memory exhaustion and panic) by creating a large number of connected file descriptors or socketpairs and setting a large data transfer buffer, then preventing Linux from being able to finish the transfer by causing the process to become a zombie, or closing the file descriptor without closing an associated reference.