From b98333c67daf887c724cd692e88e2db9418c0861 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Fri, 4 Oct 2024 11:13:38 -0400 Subject: dlm: fix possible lkb_resource null dereference This patch fixes a possible null pointer dereference when this function is called from request_lock() as lkb->lkb_resource is not assigned yet, only after validate_lock_args() by calling attach_lkb(). Another issue is that a resource name could be a non printable bytearray and we cannot assume to be ASCII coded. The log functionality is probably never being hit when DLM is used in normal way and no debug logging is enabled. The null pointer dereference can only occur on a new created lkb that does not have the resource assigned yet, it probably never hits the null pointer dereference but we should be sure that other changes might not change this behaviour and we actually can hit the mentioned null pointer dereference. In this patch we just drop the printout of the resource name, the lkb id is enough to make a possible connection to a resource name if this exists. Signed-off-by: Alexander Aring Signed-off-by: David Teigland --- fs/dlm/lock.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'fs/dlm/lock.c') diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index 865dc70a9dfc..dddedaef5e93 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -2861,16 +2861,14 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, case -EINVAL: /* annoy the user because dlm usage is wrong */ WARN_ON(1); - log_error(ls, "%s %d %x %x %x %d %d %s", __func__, + log_error(ls, "%s %d %x %x %x %d %d", __func__, rv, lkb->lkb_id, dlm_iflags_val(lkb), args->flags, - lkb->lkb_status, lkb->lkb_wait_type, - lkb->lkb_resource->res_name); + lkb->lkb_status, lkb->lkb_wait_type); break; default: - log_debug(ls, "%s %d %x %x %x %d %d %s", __func__, + log_debug(ls, "%s %d %x %x %x %d %d", __func__, rv, lkb->lkb_id, dlm_iflags_val(lkb), args->flags, - lkb->lkb_status, lkb->lkb_wait_type, - lkb->lkb_resource->res_name); + lkb->lkb_status, lkb->lkb_wait_type); break; } -- cgit v1.2.3