--- x/mm/oom_kill.c
+++ y/mm/oom_kill.c
@@ -997,6 +997,8 @@ static void __oom_kill_process(struct ta
 		queue_oom_reaper(victim);
 
 	mmdrop(mm);
+	write_lock_irq(&tasklist_lock);
+	write_unlock_irq(&tasklist_lock);
 	put_task_struct(victim);
 }
 
@@ -1031,6 +1033,8 @@ static void oom_kill_process(struct oom_
 		mark_oom_victim(victim);
 		queue_oom_reaper(victim);
 		task_unlock(victim);
+		write_lock_irq(&tasklist_lock);
+		write_unlock_irq(&tasklist_lock);
 		put_task_struct(victim);
 		return;
 	}
--- x/mm/page-writeback.c
+++ y/mm/page-writeback.c
@@ -3014,7 +3014,7 @@ bool __folio_end_writeback(struct folio
 
 	if (mapping && mapping_use_writeback_tags(mapping)) {
 		struct inode *inode = mapping->host;
-		struct bdi_writeback *wb = inode_to_wb(inode);
+		struct bdi_writeback *wb;
 		unsigned long flags;
 
 		xa_lock_irqsave(&mapping->i_pages, flags);
@@ -3022,6 +3022,7 @@ bool __folio_end_writeback(struct folio
 		__xa_clear_mark(&mapping->i_pages, folio_index(folio),
 					PAGECACHE_TAG_WRITEBACK);
 
+		wb = inode_to_wb(inode);
 		wb_stat_mod(wb, WB_WRITEBACK, -nr);
 		__wb_writeout_add(wb, nr);
 		if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) {
@@ -3054,7 +3055,7 @@ void __folio_start_writeback(struct foli
 	if (mapping && mapping_use_writeback_tags(mapping)) {
 		XA_STATE(xas, &mapping->i_pages, folio_index(folio));
 		struct inode *inode = mapping->host;
-		struct bdi_writeback *wb = inode_to_wb(inode);
+		struct bdi_writeback *wb;
 		unsigned long flags;
 		bool on_wblist;
 
@@ -3065,6 +3066,7 @@ void __folio_start_writeback(struct foli
 		on_wblist = mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK);
 
 		xas_set_mark(&xas, PAGECACHE_TAG_WRITEBACK);
+		wb = inode_to_wb(inode);
 		wb_stat_mod(wb, WB_WRITEBACK, nr);
 		if (!on_wblist) {
 			wb_inode_writeback_start(wb);