[PATCH V2 5/6] File /proc//numa_vamaps access needs PTRACE_MODE_READ_REALCREDS check

[Prakash Sangappa]

Permission to access /proc/<pid>/numa_vamaps file should be governed by
PTRACE_READ_REALCREADS check to restrict getting specific VA range to numa
node mapping information.

Signed-off-by: Prakash Sangappa <prakash.sanga...@oracle.com>
Reviewed-by: Steve Sistare <steven.sist...@oracle.com>
---
 fs/proc/base.c     | 4 +++-
 fs/proc/task_mmu.c | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 1af99ae..3c19a55 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -745,7 +745,9 @@ struct mm_struct *proc_mem_open(struct inode *inode, 
unsigned int mode)
        struct mm_struct *mm = ERR_PTR(-ESRCH);
 
        if (task) {
-               mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
+               if (!(mode & PTRACE_MODE_REALCREDS))
+                       mode |= PTRACE_MODE_FSCREDS;
+               mm = mm_access(task, mode);
                put_task_struct(task);
 
                if (!IS_ERR_OR_NULL(mm)) {
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 93dce46..30b29d2 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -2043,7 +2043,7 @@ static int numa_vamaps_open(struct inode *inode, struct 
file *file)
        if (!nvm)
                return -ENOMEM;
 
-       mm = proc_mem_open(inode, PTRACE_MODE_READ);
+       mm = proc_mem_open(inode, PTRACE_MODE_READ | PTRACE_MODE_REALCREDS);
        if (IS_ERR(mm)) {
                kfree(nvm);
                return PTR_ERR(mm);
-- 
2.7.4