2017-11-25 19:39:02 -05:00

33 lines
1.0 KiB
Diff

From 57bc19ec472ab303209b2d96a59a619c5221594d Mon Sep 17 00:00:00 2001
From: Andrew Chant <achant@google.com>
Date: Wed, 8 Feb 2017 15:33:48 -0800
Subject: [PATCH] sdcardfs: limit stacking depth
Limit filesystem stacking to prevent stack overflow.
Bug: 32761463
Change-Id: I8b1462b9c0d6c7f00cf110724ffb17e7f307c51e
Signed-off-by: Andrew Chant <achant@google.com>
---
fs/sdcardfs/main.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/sdcardfs/main.c b/fs/sdcardfs/main.c
index a6522286d7314..8b51a124298f4 100755
--- a/fs/sdcardfs/main.c
+++ b/fs/sdcardfs/main.c
@@ -223,6 +223,13 @@ static int sdcardfs_read_super(struct super_block *sb, const char *dev_name,
atomic_inc(&lower_sb->s_active);
sdcardfs_set_lower_super(sb, lower_sb);
+ sb->s_stack_depth = lower_sb->s_stack_depth + 1;
+ if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
+ pr_err("sdcardfs: maximum fs stacking depth exceeded\n");
+ err = -EINVAL;
+ goto out_sput;
+ }
+
/* inherit maxbytes from lower file system */
sb->s_maxbytes = lower_sb->s_maxbytes;