Linux vulnerabilities

The __block_prepare_write function in fs/buffer.c for Linux kernel 2.6.x before 2.6.13 does not properly clear buffers during certain error conditions, which allows local users to read portions of files that have been unlinked.

The copy_from_user function in the uaccess code in Linux kernel 2.6 before 2.6.19-rc1, when running on s390, does not properly clear a kernel buffer, which allows local user space programs to read portions of kernel memory by "appending to a file from a bad address," which triggers a fault that prevents the unused memory from being cleared in the kernel buffer.

The clip_mkip function in net/atm/clip.c of the ATM subsystem in Linux kernel allows remote attackers to cause a denial of service (panic) via unknown vectors that cause the ATM subsystem to access the memory of socket buffers after they are freed (freed pointer dereference).

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).

The nlmclnt_mark_reclaim in clntlock.c in NFS lockd in Linux kernel before 2.6.16 allows remote attackers to cause a denial of service (process crash) and deny access to NFS exports via unspecified vectors that trigger a kernel oops (null dereference) and a deadlock.

The Linux kernel 2.6.17.10 and 2.6.17.11 and 2.6.18-rc5 allows local users to cause a denial of service (crash) via an SCTP socket with a certain SO_LINGER value, possibly related to the patch for CVE-2006-3745. NOTE: older kernel versions for specific Linux distributions are also affected, due to backporting of the CVE-2006-3745 patch.

The Unidirectional Lightweight Encapsulation (ULE) decapsulation component in dvb-core/dvb_net.c in the dvb driver in the Linux kernel 2.6.17.8 allows remote attackers to cause a denial of service (crash) via an SNDU length of 0 in a ULE packet.

The source code tar archive of the Linux kernel 2.6.16, 2.6.17.11, and possibly other versions specifies weak permissions (0666 and 0777) for certain files and directories, which might allow local users to insert Trojan horse source code that would be used during the next kernel compilation. NOTE: another researcher disputes the vulnerability, stating that he finds "Not a single world-writable file or directory." CVE analysis as of 20060908 indicates that permissions will only be weak under certain unusual or insecure scenarios

Linux kernel 2.6.17 and earlier, when running on IA64 or SPARC platforms, allows local users to cause a denial of service (crash) via a malformed ELF file that triggers memory maps that cross region boundaries.

Unspecified vulnerability in the sctp_make_abort_user function in the SCTP implementation in Linux 2.6.x before 2.6.17.10 and 2.4.23 up to 2.4.33 allows local users to cause a denial of service (panic) and possibly gain root privileges via unknown attack vectors.

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.

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 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.

Race condition between the kfree_skb and __skb_unlink functions in the socket buffer handling in Linux kernel 2.6.9, and possibly other versions, allows remote attackers to cause a denial of service (crash), as demonstrated using the TCP stress tests from the LTP test suite.

The (1) __futex_atomic_op and (2) futex_atomic_cmpxchg_inatomic functions in Linux kernel 2.6.17-rc4 to 2.6.18-rc2 perform the atomic futex operation in the kernel address space instead of the user address space, which allows local users to cause a denial of service (crash).

Linux kernel 2.6.x, when using both NFS and EXT3, allows remote attackers to cause a denial of service (file system panic) via a crafted UDP packet with a V2 lookup procedure that specifies a bad file handle (inode number), which triggers an error and causes an exported directory to be remounted read-only.

Race condition in Linux kernel 2.6.17.4 and earlier allows local users to gain root privileges by using prctl with PR_SET_DUMPABLE in a way that causes /proc/self/environ to become setuid root.

The ftdi_sio driver (usb/serial/ftdi_sio.c) in Linux kernel 2.6.x up to 2.6.17, and possibly later versions, allows local users to cause a denial of service (memory consumption) by writing more data to the serial port than the hardware can handle, which causes the data to be queued.

The suid_dumpable support in Linux kernel 2.6.13 up to versions before 2.6.17.4, and 2.6.16 before 2.6.16.24, allows a local user to cause a denial of service (disk consumption) and possibly gain privileges via the PR_SET_DUMPABLE argument of the prctl function and a program that causes a core dump file to be created in a directory for which the user does not have permissions.

The dvd_read_bca function in the DVD handling code in drivers/cdrom/cdrom.c in Linux kernel 2.2.16, and later versions, assigns the wrong value to a length variable, which allows local users to execute arbitrary code via a crafted USB Storage device that triggers a buffer overflow.

SCTP conntrack (ip_conntrack_proto_sctp.c) in netfilter for Linux kernel 2.6.17 before 2.6.17.3 and 2.6.16 before 2.6.16.23 allows remote attackers to cause a denial of service (crash) via a packet without any chunks, which causes a variable to contain an invalid value that is later used to dereference a pointer.

The strnlen_user function in Linux kernel before 2.6.16 on IBM S/390 can return an incorrect value, which allows local users to cause a denial of service via unknown vectors.

xt_sctp in netfilter for Linux kernel before 2.6.17.1 allows attackers to cause a denial of service (infinite loop) via an SCTP chunk with a 0 length.

Linux kernel before 2.6.16.21 and 2.6.17, when running on PowerPC, does not perform certain required access_ok checks, which allows local users to read arbitrary kernel memory on 64-bit systems (signal_64.c) and cause a denial of service (crash) and possibly read kernel memory on 32-bit systems (signal_32.c).

Race condition in run_posix_cpu_timers in Linux kernel before 2.6.16.21 allows local users to cause a denial of service (BUG_ON crash) by causing one CPU to attach a timer to a process that is exiting.

Race condition in Linux kernel 2.6.15 to 2.6.17, when running on SMP platforms, allows local users to cause a denial of service (crash) by creating and exiting a large number of tasks, then accessing the /proc entry of a task that is exiting, which causes memory corruption that leads to a failure in the prune_dcache function or a BUG_ON error in include/linux/list.h.

The snmp_trap_decode function in the SNMP NAT helper for Linux kernel before 2.6.16.18 allows remote attackers to cause a denial of service (crash) via unspecified remote attack vectors that cause failures in snmp_trap_decode that trigger (1) frees of random memory or (2) frees of previously-freed memory (double-free) by snmp_trap_decode as well as its calling function, as demonstrated via certain test cases of the PROTOS SNMP test suite.

The virtual memory implementation in Linux kernel 2.6.x allows local users to cause a denial of service (panic) by running lsof a large number of times in a way that produces a heavy system load.

SCTP in Linux kernel before 2.6.16.17 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a chunk length that is inconsistent with the actual length of provided parameters.

Buffer overflow in SCTP in Linux kernel before 2.6.16.17 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a malformed HB-ACK chunk.

Certain modifications to the Linux kernel 2.6.16 and earlier do not add the appropriate Linux Security Modules (LSM) file_permission hooks to the (1) readv and (2) writev functions, which might allow attackers to bypass intended access restrictions.

Race condition in the do_add_counters function in netfilter for Linux kernel 2.6.16 allows local users with CAP_NET_ADMIN capabilities to read kernel memory by triggering the race condition in a way that produces a size value that is inconsistent with allocated memory, which leads to a buffer over-read in IPT_ENTRY_ITERATE.

choose_new_parent in Linux kernel before 2.6.11.12 includes certain debugging code, which allows local users to cause a denial of service (panic) by causing certain circumstances involving termination of a parent process.

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.

lease_init in fs/locks.c in Linux kernel before 2.6.16.16 allows attackers to cause a denial of service (fcntl_setlease lockup) via actions that cause lease_init to free a lock that might not have been allocated on the stack.

Memory leak in __setlease in fs/locks.c in Linux kernel before 2.6.16.16 allows attackers to cause a denial of service (memory consumption) via unspecified actions related to an "uninitialised return value," aka "slab leak."

The selinux_ptrace logic in hooks.c in SELinux for Linux 2.6.6 allows local users with ptrace permissions to change the tracer SID to an SID of another process.

The SCTP-netfilter code in Linux kernel before 2.6.16.13 allows remote attackers to trigger a denial of service (infinite loop) via unknown vectors that cause an invalid SCTP chunk size to be processed by the for_each_sctp_chunk function.

Linux kernel 2.4.x and 2.6.x up to 2.6.16 allows local users to bypass IPC permissions and modify a readonly attachment of shared memory by using mprotect to give write permission to the attachment. NOTE: some original raw sources combined this issue with CVE-2006-1524, but they are different bugs.

Directory traversal vulnerability in smbfs in Linux 2.6.16 and earlier allows local users to escape chroot restrictions for an SMB-mounted filesystem via "..\\" sequences, a similar vulnerability to CVE-2006-1863.

Directory traversal vulnerability in CIFS in Linux 2.6.16 and earlier allows local users to escape chroot restrictions for an SMB-mounted filesystem via "..\\" sequences, a similar vulnerability to CVE-2006-1864.

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.

madvise_remove in Linux kernel 2.6.16 up to 2.6.16.6 does not follow file and mmap restrictions, which allows local users to bypass IPC permissions and replace portions of readonly tmpfs files with zeroes, aka the MADV_REMOVE vulnerability. NOTE: this description was originally written in a way that combined two separate issues. The mprotect issue now has a separate name, CVE-2006-2071.

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.

The __group_complete_signal function in the RCU signal handling (signal.c) in Linux kernel 2.6.16, and possibly other versions, has unknown impact and attack vectors related to improper use of BUG_ON.

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.

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 default configuration of syslogd in the Linux sysklogd package does not enable the -x (disable name lookups) option, which allows remote attackers to cause a denial of service (traffic amplification) via messages with spoofed source IP addresses.