Buffer overflow in nfsd in the Linux kernel before 2.6.26.4, when NFSv4 is enabled, allows remote attackers to have an unknown impact via vectors related to decoding an NFSv4 acl.

The pppol2tp_recvmsg function in drivers/net/pppol2tp.c in the Linux kernel 2.6 before 2.6.26-rc6 allows remote attackers to cause a denial of service (kernel heap memory corruption and system crash) and possibly have unspecified other impact via a crafted PPPOL2TP packet that results in a large value for a certain length variable.

The utimensat system call (sys_utimensat) in Linux kernel 2.6.22 and other versions before 2.6.25.3 does not check file permissions when certain UTIME_NOW and UTIME_OMIT combinations are used, which allows local users to modify file times of arbitrary files, possibly leading to a denial of service.

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.

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 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.