diff options
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 50 |
1 files changed, 32 insertions, 18 deletions
diff --git a/fs/exec.c b/fs/exec.c index cce6bbdbdbb..49cdaa19e5b 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -195,7 +195,7 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, * to work from. */ rlim = current->signal->rlim; - if (size > rlim[RLIMIT_STACK].rlim_cur / 4) { + if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { put_page(page); return NULL; } @@ -246,6 +246,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm) vma->vm_start = vma->vm_end - PAGE_SIZE; vma->vm_flags = VM_STACK_FLAGS; vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); + INIT_LIST_HEAD(&vma->anon_vma_chain); err = insert_vm_struct(mm, vma); if (err) goto err; @@ -516,7 +517,8 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) /* * cover the whole range: [new_start, old_end) */ - vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL); + if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) + return -ENOMEM; /* * move the page tables downwards, on failure we rely on @@ -547,15 +549,13 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) tlb_finish_mmu(tlb, new_end, old_end); /* - * shrink the vma to just the new range. + * Shrink the vma to just the new range. Always succeeds. */ vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); return 0; } -#define EXTRA_STACK_VM_PAGES 20 /* random */ - /* * Finalizes the stack vm_area_struct. The flags and permissions are updated, * the stack is optionally relocated, and some extra space is added. @@ -577,7 +577,7 @@ int setup_arg_pages(struct linux_binprm *bprm, #ifdef CONFIG_STACK_GROWSUP /* Limit stack size to 1GB */ - stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max; + stack_base = rlimit_max(RLIMIT_STACK); if (stack_base > (1 << 30)) stack_base = 1 << 30; @@ -630,7 +630,7 @@ int setup_arg_pages(struct linux_binprm *bprm, goto out_unlock; } - stack_expand = EXTRA_STACK_VM_PAGES * PAGE_SIZE; + stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ stack_size = vma->vm_end - vma->vm_start; /* * Align this down to a page boundary as expand_stack @@ -718,6 +718,7 @@ static int exec_mmap(struct mm_struct *mm) /* Notify parent that we're no longer interested in the old VM */ tsk = current; old_mm = current->mm; + sync_mm_rss(tsk, old_mm); mm_release(tsk, old_mm); if (old_mm) { @@ -1532,7 +1533,7 @@ static int format_corename(char *corename, long signr) /* core limit size */ case 'c': rc = snprintf(out_ptr, out_end - out_ptr, - "%lu", current->signal->rlim[RLIMIT_CORE].rlim_cur); + "%lu", rlimit(RLIMIT_CORE)); if (rc > out_end - out_ptr) goto out; out_ptr += rc; @@ -1560,12 +1561,13 @@ out: return ispipe; } -static int zap_process(struct task_struct *start) +static int zap_process(struct task_struct *start, int exit_code) { struct task_struct *t; int nr = 0; start->signal->flags = SIGNAL_GROUP_EXIT; + start->signal->group_exit_code = exit_code; start->signal->group_stop_count = 0; t = start; @@ -1590,8 +1592,7 @@ static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, spin_lock_irq(&tsk->sighand->siglock); if (!signal_group_exit(tsk->signal)) { mm->core_state = core_state; - tsk->signal->group_exit_code = exit_code; - nr = zap_process(tsk); + nr = zap_process(tsk, exit_code); } spin_unlock_irq(&tsk->sighand->siglock); if (unlikely(nr < 0)) @@ -1640,7 +1641,7 @@ static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, if (p->mm) { if (unlikely(p->mm == mm)) { lock_task_sighand(p, &flags); - nr += zap_process(p); + nr += zap_process(p, exit_code); unlock_task_sighand(p, &flags); } break; @@ -1747,14 +1748,19 @@ void set_dumpable(struct mm_struct *mm, int value) } } -int get_dumpable(struct mm_struct *mm) +static int __get_dumpable(unsigned long mm_flags) { int ret; - ret = mm->flags & 0x3; + ret = mm_flags & MMF_DUMPABLE_MASK; return (ret >= 2) ? 2 : ret; } +int get_dumpable(struct mm_struct *mm) +{ + return __get_dumpable(mm->flags); +} + static void wait_for_dump_helpers(struct file *file) { struct pipe_inode_info *pipe; @@ -1797,7 +1803,13 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs) struct coredump_params cprm = { .signr = signr, .regs = regs, - .limit = current->signal->rlim[RLIMIT_CORE].rlim_cur, + .limit = rlimit(RLIMIT_CORE), + /* + * We must use the same mm->flags while dumping core to avoid + * inconsistency of bit flags, since this flag is not protected + * by any locks. + */ + .mm_flags = mm->flags, }; audit_core_dumps(signr); @@ -1816,7 +1828,7 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs) /* * If another thread got here first, or we are not dumpable, bail out. */ - if (mm->core_state || !get_dumpable(mm)) { + if (mm->core_state || !__get_dumpable(cprm.mm_flags)) { up_write(&mm->mmap_sem); put_cred(cred); goto fail; @@ -1827,7 +1839,8 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs) * process nor do we know its entire history. We only know it * was tainted so we dump it as root in mode 2. */ - if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ + if (__get_dumpable(cprm.mm_flags) == 2) { + /* Setuid core dump mode */ flag = O_EXCL; /* Stop rewrite attacks */ cred->fsuid = 0; /* Dump root private */ } @@ -1923,8 +1936,9 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs) /* * Dont allow local users get cute and trick others to coredump * into their pre-created files: + * Note, this is not relevant for pipes */ - if (inode->i_uid != current_fsuid()) + if (!ispipe && (inode->i_uid != current_fsuid())) goto close_fail; if (!cprm.file->f_op) goto close_fail; |