The skb_gro_header_slow function in include/linux/netdevice.h in the Linux kernel before 2.6.39.4, when Generic Receive Offload is enabled, resets certain fields in incorrect situations, which allows remote attackers to cause a denial of service via crafted network traffic. Race condition in the ecryptfs_mount function in fs/ecryptfs/main.c in the eCryptfs subsystem in the Linux kernel before 3.1 allows local users to bypass intended file permissions via a mount.ecryptfs_private mount with a mismatched uid. The IPv4 and IPv6 implementations in the Linux kernel before 3.1 use a modified MD4 algorithm to generate sequence numbers and Fragment Identification values, which makes it easier for remote attackers to cause a denial of service or hijack network sessions by predicting these values and sending crafted packets. Integer signedness error in the CIFSFindNext function in fs/cifs/cifssmb.c in the Linux kernel before 3.1 allows remote CIFS servers to cause a denial of service or possibly have unspecified other impact via a large length value in a response to a read request for a directory. The Performance Events subsystem in the Linux kernel before 3.1 does not properly handle event overflows associated with PERF_COUNT_SW_CPU_CLOCK events, which allows local users to cause a denial of service via a crafted application.