mm: /proc/pid/smaps_rollup: fix no vma's null-deref

Commit 258f669 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") introduced a null-deref if there are no vma's in the task in show_smaps_rollup. Fixes: 258f669 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") Signed-off-by: Seth Jenkins <[email protected]> Reviewed-by: Alexey Dobriyan <[email protected]> Tested-by: Alexey Dobriyan <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
sirdarckcat · Oct 29, 2022 · 33fc9e2 · 33fc9e2
1 parent b9d8cbe
commit 33fc9e2
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
@@ -951,7 +951,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
 		vma = vma->vm_next;
 	}
 
-	show_vma_header_prefix(m, priv->mm->mmap->vm_start,
+	show_vma_header_prefix(m, priv->mm->mmap ? priv->mm->mmap->vm_start : 0,
 			       last_vma_end, 0, 0, 0, 0);
 	seq_pad(m, ' ');
 	seq_puts(m, "[rollup]\n");