[PATCH 18/24] sys:__sys_setuid(): handle fsid mappings
From: Christian Brauner <hidden>
Date: 2020-02-11 17:00:11
Also in:
linux-fsdevel, linux-security-module, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Switch setuid() to lookup fsids in the fsid mappings. If no fsid mappings are setup the behavior is unchanged, i.e. fsids are looked up in the id mappings. Signed-off-by: Christian Brauner <redacted> --- kernel/sys.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/kernel/sys.c b/kernel/sys.c
index b89334ad0908..afaec8d46bc5 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c@@ -574,11 +574,16 @@ long __sys_setuid(uid_t uid) struct cred *new; int retval; kuid_t kuid; + kuid_t kfsuid; kuid = make_kuid(ns, uid); if (!uid_valid(kuid)) return -EINVAL; + kfsuid = make_kfsuid(ns, uid); + if (!uid_valid(kfsuid)) + return -EINVAL; + new = prepare_creds(); if (!new) return -ENOMEM;
@@ -596,7 +601,8 @@ long __sys_setuid(uid_t uid) goto error; } - new->fsuid = new->euid = kuid; + new->euid = kuid; + new->fsuid = kfsuid; retval = security_task_fix_setuid(new, old, LSM_SETID_ID); if (retval < 0)
--
2.25.0