At line 294 in drivers/lightnvm/pblk-write.c, function pblk_gen_run_ws is called with actual param GFP_ATOMIC. pblk_gen_run_ws call mempool_alloc using "GFP_ATOMIC" flag, so mempool_alloc can return null. So we need to check the return-val of mempool_alloc to avoid null-ptr-deref bug.

Signed-off-by: tangzhenhao <redacted>
---
  drivers/lightnvm/pblk-core.c | 4 ++++
  1 file changed, 4 insertions(+)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 97c68731406b..1dddba11e721 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c

@@ -1869,6 +1869,10 @@ void pblk_gen_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
  	struct pblk_line_ws *line_ws;
  
  	line_ws = mempool_alloc(&pblk->gen_ws_pool, gfp_mask);
+	if (!line_ws) {
+		pblk_err(pblk, "pblk: could not allocate memory\n");
+		return;
+	}
  
  	line_ws->pblk = pblk;
  	line_ws->line = line;