[PATCH 08/16] binfmt_misc: use credential guards
From: Christian Brauner <brauner@kernel.org>
Date: 2025-11-03 11:27:30
Also in:
cgroups, linux-cifs, linux-fsdevel, linux-nfs, linux-unionfs, lkml
Subsystem:
exec & binfmt api, elf, filesystems (vfs and infrastructure), the rest · Maintainers:
Kees Cook, Alexander Viro, Christian Brauner, Linus Torvalds
Use credential guards for scoped credential override with automatic restoration on scope exit. Signed-off-by: Christian Brauner <brauner@kernel.org> --- fs/binfmt_misc.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index a839f960cd4a..558db4bd6c2a 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c@@ -782,8 +782,6 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer, return PTR_ERR(e); if (e->flags & MISC_FMT_OPEN_FILE) { - const struct cred *old_cred; - /* * Now that we support unprivileged binfmt_misc mounts make * sure we use the credentials that the register @file was
@@ -791,9 +789,8 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer, * didn't matter much as only a privileged process could open * the register file. */ - old_cred = override_creds(file->f_cred); - f = open_exec(e->interpreter); - revert_creds(old_cred); + scoped_with_creds(file->f_cred) + f = open_exec(e->interpreter); if (IS_ERR(f)) { pr_notice("register: failed to install interpreter file %s\n", e->interpreter);
--
2.47.3