From a50ed2d28727ff605d95fb9a53be8ff94e8eaaf4 Mon Sep 17 00:00:00 2001
From: Seth Jenkins <sethjenkins@google.com>
Date: Thu, 27 Oct 2022 11:36:52 -0400
Subject: [PATCH] mm: /proc/pid/smaps_rollup: fix no vma's null-deref
Commit 258f669e7e88 ("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: 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file")
Signed-off-by: Seth Jenkins <sethjenkins@google.com>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Tested-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/proc/task_mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ef18f0d71b11b..8b75a04836b63 100644
--- 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");
--
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