linux-ext4 - [RFC PATCH 01/14] ext4: Clear BH_Uptodate flag on decryption error

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190412171041.31995-2-chandan@linux.ibm.com>
Date:   Fri, 12 Apr 2019 22:40:28 +0530
From:   Chandan Rajendra <chandan@...ux.ibm.com>
To:     linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net,
        linux-fscrypt@...r.kernel.org
Cc:     Chandan Rajendra <chandan@...ux.ibm.com>, tytso@....edu,
        adilger.kernel@...ger.ca, ebiggers@...nel.org, jaegeuk@...nel.org,
        yuchao0@...wei.com
Subject: [RFC PATCH 01/14] ext4: Clear BH_Uptodate flag on decryption error

On an error return from fscrypt_decrypt_page(), ext4_block_write_begin()
can return with the page's buffer_head marked with BH_Uptodate
flag. This commit clears the BH_Uptodate flag in such cases.

Signed-off-by: Chandan Rajendra <chandan@...ux.ibm.com>
---
 fs/ext4/inode.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 3c2e7f5a6c84..05b258db8673 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1225,11 +1225,15 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
 		if (!buffer_uptodate(*wait_bh))
 			err = -EIO;
 	}
-	if (unlikely(err))
+	if (unlikely(err)) {
 		page_zero_new_buffers(page, from, to);
-	else if (decrypt)
+	} else if (decrypt) {
 		err = fscrypt_decrypt_page(page->mapping->host, page,
 				PAGE_SIZE, 0, page->index);
+		if (err)
+			clear_buffer_uptodate(*wait_bh);
+	}
+
 	return err;
 }
 #endif
-- 
2.19.1