From: John Stultz <john.stultz@xxxxxxxxxx>
Using old_creds as an indication that we are not overriding the
credentials, bypass call to inode_owner_or_capable. This solves
a problem with all execv calls being blocked when using the caller's
credentials.
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
Signed-off-by: Mark Salyzyn <salyzyn@xxxxxxxxxxx>
Fixes: 05acefb4872da ("ovl: check permission to open real file")
C: linux-fsdevel@xxxxxxxxxxxxxxx
C: linux-unionfs@xxxxxxxxxxxxxxx
Cc: Stephen Smalley <sds@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-security-module@xxxxxxxxxxxxxxx
Cc: kernel-team@xxxxxxxxxxx
Cc: selinux@xxxxxxxxxxxxxxx
v18 - rebase
v17 - rebase
v16 - introduced fix over rebased series
---
fs/overlayfs/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index b1357bb067d9..9ab9663b02d8 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -53,7 +53,7 @@ static struct file *ovl_open_realfile(const struct file *file,
err = inode_permission(realinode, MAY_OPEN | acc_mode);
if (err) {
realfile = ERR_PTR(err);
- } else if (!inode_owner_or_capable(realinode)) {
+ } else if (old_cred && !inode_owner_or_capable(realinode)) {
realfile = ERR_PTR(-EPERM);
} else {
realfile = open_with_fake_path(&file->f_path, flags, realinode,
--
2.29.0.rc1.297.gfa9743e501-goog
