path: root/fs
diff options
authorChristopher Yeoh <cyeoh@au1.ibm.com>2012-02-02 11:34:09 +1030
committerLinus Torvalds <torvalds@linux-foundation.org>2012-02-02 12:55:17 -0800
commit8cdb878dcb359fd1137e9abdee9322f5e9bcfdf8 (patch)
tree146afc01f3c1d7cbc944328484d077032bc53bfd /fs
parent24b36da33c64368775f4ef9386d44dce1d2bc8cf (diff)
Fix race in process_vm_rw_core
This fixes the race in process_vm_core found by Oleg (see http://article.gmane.org/gmane.linux.kernel/1235667/ for details). This has been updated since I last sent it as the creation of the new mm_access() function did almost exactly the same thing as parts of the previous version of this patch did. In order to use mm_access() even when /proc isn't enabled, we move it to kernel/fork.c where other related process mm access functions already are. Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
1 files changed, 0 insertions, 20 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index d9512bd03e6c..d4548dd49b02 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -198,26 +198,6 @@ static int proc_root_link(struct dentry *dentry, struct path *path)
return result;
-static struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
- struct mm_struct *mm;
- int err;
- err = mutex_lock_killable(&task->signal->cred_guard_mutex);
- if (err)
- return ERR_PTR(err);
- mm = get_task_mm(task);
- if (mm && mm != current->mm &&
- !ptrace_may_access(task, mode)) {
- mmput(mm);
- mm = ERR_PTR(-EACCES);
- }
- mutex_unlock(&task->signal->cred_guard_mutex);
- return mm;
struct mm_struct *mm_for_maps(struct task_struct *task)
return mm_access(task, PTRACE_MODE_READ);

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