From: Suresh Siddha Date: Wed, 22 Jun 2005 00:14:32 +0000 (-0700) Subject: [PATCH] x86_64: TASK_SIZE fixes for compatibility mode processes X-Git-Tag: v2.6.13-rc1~68^2~582^2~163 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=84929801e14d968caeb84795bfbb88f04283fbd9;p=pandora-kernel.git [PATCH] x86_64: TASK_SIZE fixes for compatibility mode processes Appended patch will setup compatibility mode TASK_SIZE properly. This will fix atleast three known bugs that can be encountered while running compatibility mode apps. a) A malicious 32bit app can have an elf section at 0xffffe000. During exec of this app, we will have a memory leak as insert_vm_struct() is not checking for return value in syscall32_setup_pages() and thus not freeing the vma allocated for the vsyscall page. And instead of exec failing (as it has addresses > TASK_SIZE), we were allowing it to succeed previously. b) With a 32bit app, hugetlb_get_unmapped_area/arch_get_unmapped_area may return addresses beyond 32bits, ultimately causing corruption because of wrap-around and resulting in SEGFAULT, instead of returning ENOMEM. c) 32bit app doing this below mmap will now fail. mmap((void *)(0xFFFFE000UL), 0x10000UL, PROT_READ|PROT_WRITE, MAP_FIXED|MAP_PRIVATE|MAP_ANON, 0, 0); Signed-off-by: Zou Nan hai Signed-off-by: Suresh Siddha Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed