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authorMiklos Szeredi <mszeredi@redhat.com>2016-10-31 14:42:14 +0100
committerMiklos Szeredi <mszeredi@redhat.com>2016-10-31 14:42:14 +0100
commitfd3220d37b1f6f0cab6142d98b0e6c4082e63299 (patch)
tree69f329819476f64840bfa280bb83f1504efd7afd /fs/overlayfs
parenta909d3e636995ba7c349e2ca5dbb528154d4ac30 (diff)
downloadlinux-fd3220d37b1f6f0cab6142d98b0e6c4082e63299.tar.bz2
ovl: update S_ISGID when setting posix ACLs
This change fixes xfstest generic/375, which failed to clear the setgid bit in the following test case on overlayfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Reported-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Amir Goldstein <amir73il@gmail.com> Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Cc: <stable@vger.kernel.org> # v4.8
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/super.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index bcf3965be819..edd46a0e951d 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1037,6 +1037,21 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler,
posix_acl_release(acl);
+ /*
+ * Check if sgid bit needs to be cleared (actual setacl operation will
+ * be done with mounter's capabilities and so that won't do it for us).
+ */
+ if (unlikely(inode->i_mode & S_ISGID) &&
+ handler->flags == ACL_TYPE_ACCESS &&
+ !in_group_p(inode->i_gid) &&
+ !capable_wrt_inode_uidgid(inode, CAP_FSETID)) {
+ struct iattr iattr = { .ia_valid = ATTR_KILL_SGID };
+
+ err = ovl_setattr(dentry, &iattr);
+ if (err)
+ return err;
+ }
+
err = ovl_xattr_set(dentry, handler->name, value, size, flags);
if (!err)
ovl_copyattr(ovl_inode_real(inode, NULL), inode);