Linux vulnerabilities

The Xen hypervisor block backend driver for Linux kernel 2.6.18, when running on a 64-bit host with a 32-bit paravirtualized guest, allows local privileged users in the guest OS to cause a denial of service (host OS crash) via a request that specifies a large number of blocks.

The bdx_ioctl_priv function in the tehuti driver (tehuti.c) in Linux kernel 2.6.x before 2.6.25.1 does not properly check certain information related to register size, which has unspecified impact and local attack vectors, probably related to reading or writing kernel memory.

Race condition in the directory notification subsystem (dnotify) in Linux kernel 2.6.x before 2.6.24.6, and 2.6.25 before 2.6.25.1, allows local users to cause a denial of service (OOPS) and possibly gain privileges via unspecified vectors.

Linux kernel 2.6.17, and other versions before 2.6.22, does not check when a user attempts to set RLIMIT_CPU to 0 until after the change is made, which allows local users to bypass intended resource limits.

Integer overflow in the hrtimer_forward function (hrtimer.c) in Linux kernel 2.6.21-rc4, when running on 64-bit systems, allows local users to cause a denial of service (infinite loop) via a timer with a large expiry value, which causes the timer to always be expired.

arch/s390/kernel/ptrace.c in Linux kernel 2.6.9, and other versions before 2.6.27-rc6, on s390 platforms allows local users to cause a denial of service (kernel panic) via the user-area-padding test from the ptrace testsuite in 31-bit mode, which triggers an invalid dereference.

The vmsplice_to_pipe function in Linux kernel 2.6.17 through 2.6.24.1 does not validate a certain userspace pointer before dereference, which allows local users to gain root privileges via crafted arguments in a vmsplice system call, a different vulnerability than CVE-2008-0009 and CVE-2008-0010.

Linux kernel 2.6, when using vservers, allows local users to access resources of other vservers via a symlink attack in /proc.

The copy_from_user_mmap_sem function in fs/splice.c in the Linux kernel 2.6.22 through 2.6.24 does not validate a certain userspace pointer before dereference, which allow local users to read from arbitrary kernel memory locations.

The vmsplice_to_user function in fs/splice.c in the Linux kernel 2.6.22 through 2.6.24 does not validate a certain userspace pointer before dereference, which might allow local users to access arbitrary kernel memory locations.

Linux kernel before 2.6.22.17, when using certain drivers that register a fault handler that does not perform range checks, allows local users to access kernel memory via an out-of-range offset.

cp, when running with an option to preserve symlinks on multiple OSes, allows local, user-assisted attackers to overwrite arbitrary files via a symlink attack using crafted directories containing multiple source files that are copied to the same destination.

The chrp_show_cpuinfo function (chrp/setup.c) in Linux kernel 2.4.21 through 2.6.18-53, when running on PowerPC, might allow local users to cause a denial of service (crash) via unknown vectors that cause the of_get_property function to fail, which triggers a NULL pointer dereference.

The Linux kernel 2.6.20 through 2.6.21.1 allows remote attackers to cause a denial of service (panic) via a certain IPv6 packet, possibly involving the Jumbo Payload hop-by-hop option (jumbogram).

VFS in the Linux kernel before 2.6.22.16, and 2.6.23.x before 2.6.23.14, performs tests of access mode by using the flag variable instead of the acc_mode variable, which might allow local users to bypass intended permissions and remove directories.

The ipv6_hop_jumbo function in net/ipv6/exthdrs.c in the Linux kernel before 2.6.22 does not properly validate the hop-by-hop IPv6 extended header, which allows remote attackers to cause a denial of service (NULL pointer dereference and kernel panic) via a crafted IPv6 packet.

Integer overflow in the hrtimer_start function in kernel/hrtimer.c in the Linux kernel before 2.6.23.10 allows local users to execute arbitrary code or cause a denial of service (panic) via a large relative timeout value. NOTE: some of these details are obtained from third party information.

Linux kernel 2.6.23 allows local users to create low pages in virtual userspace memory and bypass mmap_min_addr protection via a crafted executable file that calls the do_brk function.

The shmem_getpage function (mm/shmem.c) in Linux kernel 2.6.11 through 2.6.23 does not properly clear allocated memory in some rare circumstances related to tmpfs, which might allow local users to read sensitive kernel data or cause a denial of service (crash).

The isdn_ioctl function in isdn_common.c in Linux kernel 2.6.23 allows local users to cause a denial of service via a crafted ioctl struct in which iocts is not null terminated, which triggers a buffer overflow.

The do_coredump function in fs/exec.c in Linux kernel 2.4.x and 2.6.x up to 2.6.24-rc3, and possibly other versions, does not change the UID of a core dump file if it exists before a root process creates a core dump in the same location, which might allow local users to obtain sensitive information.

Buffer overflow in the isdn_net_setcfg function in isdn_net.c in Linux kernel 2.6.23 allows local users to have an unknown impact via a crafted argument to the isdn_ioctl function.

The wait_task_stopped function in the Linux kernel before 2.6.23.8 checks a TASK_TRACED bit instead of an exit_state value, which allows local users to cause a denial of service (machine crash) via unspecified vectors. NOTE: some of these details are obtained from third party information.

The tcp_sacktag_write_queue function in net/ipv4/tcp_input.c in Linux kernel 2.6.21 through 2.6.23.7, and 2.6.24-rc through 2.6.24-rc2, allows remote attackers to cause a denial of service (crash) via crafted ACK responses that trigger a NULL pointer dereference.

The skge driver 1.5 in Linux kernel 2.6.15 on Ubuntu does not properly use the spin_lock and spin_unlock functions, which allows remote attackers to cause a denial of service (machine crash) via a flood of network traffic.

Multiple buffer overflows in CIFS VFS in Linux kernel 2.6.23 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via long SMB responses that trigger the overflows in the SendReceive function.

Integer underflow in the ieee80211_rx function in net/ieee80211/ieee80211_rx.c in the Linux kernel 2.6.x before 2.6.23 allows remote attackers to cause a denial of service (crash) via a crafted SKB length value in a runt IEEE 802.11 frame when the IEEE80211_STYPE_QOS_DATA flag is set, aka an "off-by-two error."

The eHCA driver in Linux kernel 2.6 before 2.6.22, when running on PowerPC, does not properly map userspace resources, which allows local users to read portions of physical address space.

The (1) hugetlb_vmtruncate_list and (2) hugetlb_vmtruncate functions in fs/hugetlbfs/inode.c in the Linux kernel before 2.6.19-rc4 perform certain prio_tree calculations using HPAGE_SIZE instead of PAGE_SIZE units, which allows local users to cause a denial of service (panic) via unspecified vectors.

The disconnect method in the Philips USB Webcam (pwc) driver in Linux kernel 2.6.x before 2.6.22.6 "relies on user space to close the device," which allows user-assisted local attackers to cause a denial of service (USB subsystem hang and CPU consumption in khubd) by not closing the device after the disconnect is invoked. NOTE: this rarely crosses privilege boundaries, unless the attacker can convince the victim to unplug the affected device.

The ATM module in the Linux kernel before 2.4.35.3, when CLIP support is enabled, allows local users to cause a denial of service (kernel panic) by reading /proc/net/atm/arp before the CLIP module has been loaded.

The snd_mem_proc_read function in sound/core/memalloc.c in the Advanced Linux Sound Architecture (ALSA) in the Linux kernel before 2.6.22.8 does not return the correct write size, which allows local users to obtain sensitive information (kernel memory contents) via a small count argument, as demonstrated by multiple reads of /proc/driver/snd-page-alloc.

The IA32 system call emulation functionality in Linux kernel 2.4.x and 2.6.x before 2.6.22.7, when running on the x86_64 architecture, does not zero extend the eax register after the 32bit entry path to ptrace is used, which might allow local users to gain privileges by triggering an out-of-bounds access to the system call table using the %RAX register.

Race condition in the tee (sys_tee) system call in the Linux kernel 2.6.17 through 2.6.17.6 might allow local users to cause a denial of service (system crash), obtain sensitive information (kernel memory contents), or gain privileges via unspecified vectors related to a potentially dropped ipipe lock during a race between two pipe readers.

The Linux kernel 2.6.20 and 2.6.21 does not properly handle an invalid LDT segment selector in %cs (the xcs field) during ptrace single-step operations, which allows local users to cause a denial of service (NULL dereference and OOPS) via certain code that makes ptrace PTRACE_SETREGS and PTRACE_SINGLESTEP requests, related to the TRACE_IRQS_ON function, and possibly related to the arch_ptrace function.

The CIFS filesystem in the Linux kernel before 2.6.22, when Unix extension support is enabled, does not honor the umask of a process, which allows local users to gain privileges.

Linux kernel 2.4.35 and other versions allows local users to send arbitrary signals to a child process that is running at higher privileges by causing a setuid-root parent process to die, which delivers an attacker-controlled parent process death signal (PR_SET_PDEATHSIG).

The xfer_secondary_pool function in drivers/char/random.c in the Linux kernel 2.4 before 2.4.35 performs reseed operations on only the first few bytes of a buffer, which might make it easier for attackers to predict the output of the random number generator, related to incorrect use of the sizeof operator.

The drm/i915 component in the Linux kernel before 2.6.22.2, when used with i965G and later chipsets, allows local users with access to an X11 session and Direct Rendering Manager (DRM) to write to arbitrary memory locations and gain privileges via a crafted batchbuffer.

The Linux kernel before 2.6.23-rc1 checks the wrong global variable for the CIFS sec mount option, which might allow remote attackers to spoof CIFS network traffic that the client configured for security signatures, as demonstrated by lack of signing despite sec=ntlmv2i in a SetupAndX request.

Stack-based buffer overflow in the random number generator (RNG) implementation in the Linux kernel before 2.6.22 might allow local root users to cause a denial of service or gain privileges by setting the default wakeup threshold to a value greater than the output pool size, which triggers writing random numbers to the stack by the pool transfer function involving "bound check ordering". NOTE: this issue might only cross privilege boundaries in environments that have granular assignment of privileges for root.

The Distributed Lock Manager (DLM) in the cluster manager for Linux kernel 2.6.15 allows remote attackers to cause a denial of service (loss of lock services) by connecting to the DLM port, which probably prevents other processes from accessing the service.

The process scheduler in the Linux kernel 2.4 performs scheduling based on CPU billing gathered from periodic process sampling ticks, which allows local users to cause a denial of service (CPU consumption) by performing voluntary nanosecond sleeps that result in the process not being active during a clock interrupt, as described in "Secretly Monopolizing the CPU Without Superuser Privileges."

The process scheduler in the Linux kernel 2.6.16 gives preference to "interactive" processes that perform voluntary sleeps, which allows local users to cause a denial of service (CPU consumption), as described in "Secretly Monopolizing the CPU Without Superuser Privileges."

The signal handling in the Linux kernel before 2.6.22, including 2.6.2, when running on PowerPC systems using HTX, allows local users to cause a denial of service via unspecified vectors involving floating point corruption and concurrency, related to clearing of MSR bits.

The decode_choice function in net/netfilter/nf_conntrack_h323_asn1.c in the Linux kernel before 2.6.20.15, 2.6.21.x before 2.6.21.6, and before 2.6.22 allows remote attackers to cause a denial of service (crash) via an encoded, out-of-range index value for a choice field, which triggers a NULL pointer dereference.

The lcd_write function in drivers/usb/misc/usblcd.c in the Linux kernel before 2.6.22-rc7 does not limit the amount of memory used by a caller, which allows local users to cause a denial of service (memory consumption).

The sysfs_readdir function in the Linux kernel 2.6, as used in Red Hat Enterprise Linux (RHEL) 4.5 and other distributions, allows users to cause a denial of service (kernel OOPS) by dereferencing a null pointer to an inode in a dentry.

The sctp_new function in (1) ip_conntrack_proto_sctp.c and (2) nf_conntrack_proto_sctp.c in Netfilter in Linux kernel 2.6 before 2.6.20.13, and 2.6.21.x before 2.6.21.4, allows remote attackers to cause a denial of service by causing certain invalid states that trigger a NULL pointer dereference.

The random number feature in Linux kernel 2.6 before 2.6.20.13, and 2.6.21.x before 2.6.21.4, (1) does not properly seed pools when there is no entropy, or (2) uses an incorrect cast when extracting entropy, which might cause the random number generator to provide the same values after reboots on systems without an entropy source.