Re: [FD] AMD Bulldozer Linux ASLR weakness: Reducing entropy by 87.5%

2015-05-08 Thread Hector Marco-Gisbert
Hi, PaX solution has actually 16 random bits for mmap objects in 32bit systems on non affected systems. On affected systems the random bits are degraded to 2^13. Unfortunately, depending on the PaX Kernel configuration sequence, some features may not be enabled. There are sequences of PaX confi

[FD] AMD Bulldozer Linux ASLR weakness: Reducing entropy by 87.5%

2015-04-21 Thread Hector Marco-Gisbert
A security issue in Linux ASLR implementation which affects some AMD processors has been found. The issue affects to all Linux process even if they are not using shared libraries (statically compiled). The problem appears because some mmapped objects (VDSO, libraries, etc.) are poorly randomiz