Multiple buffer overflows in the cifs subsystem in the Linux kernel before 2.6.29.4 allow remote CIFS servers to cause a denial of service (memory corruption) and possibly have unspecified other impact via (1) a malformed Unicode string, related to Unicode string area alignment in fs/cifs/sess.c; or (2) long Unicode characters, related to fs/cifs/cifssmb.c and the cifs_readdir function in fs/cifs/readdir.c.