From: Christian Brauner brauner@kernel.org
commit cb2239c198ad9fbd5aced22cf93e45562da781eb upstream.
When cleaning up peer group ids in the failure path we need to make sure to hold on to the namespace lock. Otherwise another thread might just turn the mount from a shared into a non-shared mount concurrently.
Link: https://lore.kernel.org/lkml/00000000000088694505f8132d77@google.com Fixes: 2a1867219c7b ("fs: add mount_setattr()") Reported-by: syzbot+8ac3859139c685c4f597@syzkaller.appspotmail.com Cc: stable@vger.kernel.org # 5.12+ Message-Id: 20230330-vfs-mount_setattr-propagation-fix-v1-1-37548d91533b@kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/namespace.c +++ b/fs/namespace.c @@ -4121,9 +4121,9 @@ static int do_mount_setattr(struct path unlock_mount_hash();
if (kattr->propagation) { - namespace_unlock(); if (err) cleanup_group_ids(mnt, NULL); + namespace_unlock(); }
return err;