[PATCH v2 27/28] ptrace: adapt ptrace_may_access() to always uses unmapped fsids

Christian Brauner
2020-02-14T18:41:36Z

ptrace_may_access() with PTRACE_MODE_FSCREDS is only used with proc and proc
wants to use the unmapped fsids.

Cc: Jann Horn <jannh@google.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
/* v2 */
patch added
---
kernel/ptrace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 43d6179508d6..3734713cc0dd 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -304,8 +304,8 @@ static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
return 0;
rcu_read_lock();
if (mode & PTRACE_MODE_FSCREDS) {
- caller_uid = cred->fsuid;
- caller_gid = cred->fsgid;
+ caller_uid = cred->kfsuid;
+ caller_gid = cred->kfsgid;
} else {
/*
* Using the euid would make more sense here, but something
--
2.25.0