From 84929801e14d968caeb84795bfbb88f04283fbd9 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Tue, 21 Jun 2005 17:14:32 -0700 Subject: [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 --- arch/x86_64/ia32/ia32_binfmt.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'arch/x86_64/ia32') diff --git a/arch/x86_64/ia32/ia32_binfmt.c b/arch/x86_64/ia32/ia32_binfmt.c index 99b522052d1..c8131f342cf 100644 --- a/arch/x86_64/ia32/ia32_binfmt.c +++ b/arch/x86_64/ia32/ia32_binfmt.c @@ -46,7 +46,7 @@ struct elf_phdr; #define IA32_EMULATOR 1 -#define ELF_ET_DYN_BASE (TASK_UNMAPPED_32 + 0x1000000) +#define ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000) #undef ELF_ARCH #define ELF_ARCH EM_386 @@ -307,9 +307,6 @@ MODULE_AUTHOR("Eric Youngdale, Andi Kleen"); #define elf_addr_t __u32 -#undef TASK_SIZE -#define TASK_SIZE 0xffffffff - static void elf32_init(struct pt_regs *); #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1 -- cgit v1.2.3