kernel: NULL ptr dereference in multiple network drivers due to missing checks in tty code

The Linux kernel before 2.6.25.10 does not properly perform tty operations, which allows local users to cause a denial of service (system crash) or possibly gain privileges via vectors involving NULL pointer dereference of function pointers in (1) hamradio/6pack.c, (2) hamradio/mkiss.c, (3) irda/irtty-sir.c, (4) ppp_async.c, (5) ppp_synctty.c, (6) slip.c, (7) wan/x25_asy.c, and (8) wireless/strip.c in drivers/net/.

win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows local users to gain privileges via a crafted application that triggers a NULL pointer dereference, a different vulnerability than other "Vulnerability Type 2" CVEs listed in MS11-034, aka "Win32k Null Pointer De-reference Vulnerability."

nss: Missing NULL check in PK11_SignWithSymKey / ssl3_ComputeRecordMACConstantTime causes server crash

A Null pointer dereference vulnerability exists in Mozilla Network Security Services due to a missing NULL check in PK11_SignWithSymKey / ssl3_ComputeRecordMACConstantTime, which could let a remote malicious user cause a Denial of Service.