diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index a8cdd09ad53f..631af167bc51 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -992,3 +992,10 @@ unsigned long arch_align_stack(unsigned long sp) sp -= get_random_int() % 8192; return sp & ~0xf; } + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + unsigned long range_end = mm->brk + 0x02000000; + return randomize_range(mm->brk, range_end, 0) ? : mm->brk; +} + diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 98d85952f574..aa9414ed74c7 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -914,3 +914,10 @@ unsigned long arch_align_stack(unsigned long sp) sp -= get_random_int() % 8192; return sp & ~0xf; } + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + unsigned long range_end = mm->brk + 0x02000000; + return randomize_range(mm->brk, range_end, 0) ? : mm->brk; +} + diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index f0b3171842f2..043a800c8f71 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1021,6 +1021,12 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) current->mm->end_data = end_data; current->mm->start_stack = bprm->p; +#ifdef arch_randomize_brk + if (current->flags & PF_RANDOMIZE) + current->mm->brk = current->mm->start_brk = + arch_randomize_brk(current->mm); +#endif + if (current->personality & MMAP_PAGE_ZERO) { /* Why this, you ask??? Well SVr4 maps page 0 as read-only, and some applications "depend" upon this behavior. diff --git a/include/asm-x86/elf.h b/include/asm-x86/elf.h index ec42a4d2e83b..cd3204ebbbdd 100644 --- a/include/asm-x86/elf.h +++ b/include/asm-x86/elf.h @@ -285,6 +285,9 @@ struct linux_binprm; extern int arch_setup_additional_pages(struct linux_binprm *bprm, int executable_stack); +extern unsigned long arch_randomize_brk(struct mm_struct *mm); +#define arch_randomize_brk arch_randomize_brk + #endif /* __KERNEL__ */ #endif diff --git a/mm/mmap.c b/mm/mmap.c index bfa389fc6ded..d2b6d44962b7 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -251,7 +251,8 @@ asmlinkage unsigned long sys_brk(unsigned long brk) * not page aligned -Ram Gupta */ rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; - if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim) + if (rlim < RLIM_INFINITY && (brk - mm->start_brk) + + (mm->end_data - mm->start_data) > rlim) goto out; newbrk = PAGE_ALIGN(brk);