diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-08-10 09:00:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-08-10 09:00:47 -0700 |
| commit | 9bcf73f48280ef8cd7f2e38e674da47c409b9906 (patch) | |
| tree | 8f2c8de4dc437ce901c8b15f437a0394481ef44a | |
| parent | 2c661a669b3e2e34311d7965271a628671191e45 (diff) | |
| parent | 704b836cbf19e885f8366bccb2e4b0474346c02d (diff) | |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
mm_for_maps: take ->cred_guard_mutex to fix the race with exec
mm_for_maps: shift down_read(mmap_sem) to the caller
mm_for_maps: simplify, use ptrace_may_access()
| -rw-r--r-- | fs/proc/base.c | 27 | ||||
| -rw-r--r-- | fs/proc/task_mmu.c | 1 | ||||
| -rw-r--r-- | fs/proc/task_nommu.c | 1 |
3 files changed, 14 insertions, 15 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 3ce5ae9e3d2..175db258942 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -234,23 +234,20 @@ static int check_mem_permission(struct task_struct *task) struct mm_struct *mm_for_maps(struct task_struct *task) { - struct mm_struct *mm = get_task_mm(task); - if (!mm) + struct mm_struct *mm; + + if (mutex_lock_killable(&task->cred_guard_mutex)) return NULL; - down_read(&mm->mmap_sem); - task_lock(task); - if (task->mm != mm) - goto out; - if (task->mm != current->mm && - __ptrace_may_access(task, PTRACE_MODE_READ) < 0) - goto out; - task_unlock(task); + + mm = get_task_mm(task); + if (mm && mm != current->mm && + !ptrace_may_access(task, PTRACE_MODE_READ)) { + mmput(mm); + mm = NULL; + } + mutex_unlock(&task->cred_guard_mutex); + return mm; -out: - task_unlock(task); - up_read(&mm->mmap_sem); - mmput(mm); - return NULL; } static int proc_pid_cmdline(struct task_struct *task, char * buffer) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 6f61b7cc32e..9bd8be1d235 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -119,6 +119,7 @@ static void *m_start(struct seq_file *m, loff_t *pos) mm = mm_for_maps(priv->task); if (!mm) return NULL; + down_read(&mm->mmap_sem); tail_vma = get_gate_vma(priv->task); priv->tail_vma = tail_vma; diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 64a72e2e765..8f5c05d3dbd 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -189,6 +189,7 @@ static void *m_start(struct seq_file *m, loff_t *pos) priv->task = NULL; return NULL; } + down_read(&mm->mmap_sem); /* start from the Nth VMA */ for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) |