linux-kernel - Re: [PATCH v2] f2fs: avoid wrong decrypted data from disk

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: <20180830014858.GA91444@jaegeuk-macbookpro.roam.corp.google.com>
Date:   Wed, 29 Aug 2018 18:48:58 -0700
From:   Jaegeuk Kim <jaegeuk@...nel.org>
To:     linux-kernel@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net
Subject: Re: [PATCH v2] f2fs: avoid wrong decrypted data from disk

1. Create a file in an encrypted directory
2. Do GC & drop caches
3. Read stale data before its bio for metapage was not issued yet

Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
---
Change log from v1:
 - move to bio != NULL

 fs/f2fs/data.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 382c1ef9a9e4..159e411785e9 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1556,6 +1556,12 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
 				bio = NULL;
 				goto set_error_page;
 			}
+		} else if (unlikely(f2fs_encrypted_file(inode))) {
+			/*
+			 * If the page is under writeback, we need to wait for
+			 * its completion to see the correct decrypted data.
+			 */
+			f2fs_wait_on_block_writeback(F2FS_I_SB(inode), block_nr);
 		}
 
 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
-- 
2.17.0.441.gb46fe60e1d-goog