[PATCH 19/24] sys:__sys_setgid(): handle fsid mappings
STALE2427d
From: Christian Brauner <hidden>
Date: 2020-02-11 16:59:48
Also in:
linux-fsdevel, linux-security-module, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Revision v1 of 3 in this series.
Revisions (3)
- v1 current
- v2 [diff vs current]
- v3 [diff vs current]
Switch setgid() 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 | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/kernel/sys.c b/kernel/sys.c
index afaec8d46bc5..11f41e0a4974 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c@@ -416,24 +416,31 @@ long __sys_setgid(gid_t gid) const struct cred *old; struct cred *new; int retval; - kgid_t kgid; + kgid_t kgid, kfsgid; kgid = make_kgid(ns, gid); if (!gid_valid(kgid)) return -EINVAL; + kfsgid = make_kfsgid(ns, gid); + if (!gid_valid(kfsgid)) + return -EINVAL; + new = prepare_creds(); if (!new) return -ENOMEM; old = current_cred(); retval = -EPERM; - if (ns_capable(old->user_ns, CAP_SETGID)) - new->gid = new->egid = new->sgid = new->fsgid = kgid; - else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) - new->egid = new->fsgid = kgid; - else + if (ns_capable(old->user_ns, CAP_SETGID)) { + new->gid = new->egid = new->sgid = kgid; + new->fsgid = kfsgid; + } else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) { + new->egid = kgid; + new->fsgid = kfsgid; + } else { goto error; + } return commit_creds(new);
--
2.25.0