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authorLinus Torvalds <torvalds@linux-foundation.org>2009-08-10 09:00:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-08-10 09:00:47 -0700
commit9bcf73f48280ef8cd7f2e38e674da47c409b9906 (patch)
tree8f2c8de4dc437ce901c8b15f437a0394481ef44a
parent2c661a669b3e2e34311d7965271a628671191e45 (diff)
parent704b836cbf19e885f8366bccb2e4b0474346c02d (diff)
downloadconfigs-9bcf73f48280ef8cd7f2e38e674da47c409b9906.tar.gz
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.c27
-rw-r--r--fs/proc/task_mmu.c1
-rw-r--r--fs/proc/task_nommu.c1
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))