[PATCH v3 21/25] ptrace: adapt ptrace_may_access() to always uses unmapped fsids

[Christian Brauner]

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

Suggested-by: Jann Horn <jannh at google.com>
Signed-off-by: Christian Brauner <christian.brauner at ubuntu.com>
---
/* v2 */
patch added

/* v3 */
unchanged
---
 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