Linux kernel before 2.6.25.2 does not apply a certain protection mechanism for fcntl functionality, which allows local users to (1) execute code in parallel or (2) exploit a race condition to obtain "re-ordered access to the descriptor table."

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.

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

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.

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 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 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 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.