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From: Eric Biggers <ebiggers3@gmail.com>
To: David Howells <dhowells@redhat.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Eric Biggers <ebiggers@google.com>
Subject: [PATCH 16/18] fs_context: de-obfuscate control flow in fscontext_read()
Date: Sun,  8 Jul 2018 14:01:52 -0700	[thread overview]
Message-ID: <20180708210154.10423-17-ebiggers3@gmail.com> (raw)
In-Reply-To: <20180708210154.10423-1-ebiggers3@gmail.com>

From: Eric Biggers <ebiggers@google.com>

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 fs/fsopen.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/fs/fsopen.c b/fs/fsopen.c
index 1fbd8b0ca194b..dd38f6b65aace 100644
--- a/fs/fsopen.c
+++ b/fs/fsopen.c
@@ -161,20 +161,18 @@ static ssize_t fscontext_read(struct file *file,
 	if (ret < 0)
 		return ret;
 
-	ret = -ENODATA;
-	if (log->head != log->tail) {
-		index = log->tail & (logsize - 1);
-		p = log->buffer[index];
-		need_free = log->need_free & (1 << index);
-		log->buffer[index] = NULL;
-		log->need_free &= ~(1 << index);
-		log->tail++;
-		ret = 0;
+	if (log->head == log->tail) {
+		mutex_unlock(&fc->uapi_mutex);
+		return -ENODATA;
 	}
 
+	index = log->tail & (logsize - 1);
+	p = log->buffer[index];
+	need_free = log->need_free & (1 << index);
+	log->buffer[index] = NULL;
+	log->need_free &= ~(1 << index);
+	log->tail++;
 	mutex_unlock(&fc->uapi_mutex);
-	if (ret < 0)
-		return ret;
 
 	ret = -EMSGSIZE;
 	n = strlen(p);
-- 
2.18.0

  parent reply	other threads:[~2018-07-08 21:05 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-08 21:01 [PATCH vfs/for-next 00/18] fs_context fixes Eric Biggers
2018-07-08 21:01 ` [PATCH 01/18] sysfs: check return value of kernfs_get_tree() Eric Biggers
2018-07-08 21:01 ` [PATCH 02/18] fs_context: fix shrinker leak in sget_fc() Eric Biggers
2018-07-08 21:01 ` [PATCH 03/18] fs_context: fix detecting full log buffer Eric Biggers
2018-07-08 21:01 ` [PATCH 04/18] fs_context: fix fs_context leak in simple_pin_fs() Eric Biggers
2018-07-08 21:01 ` [PATCH 05/18] fs_context: fix mount option blacklist Eric Biggers
2018-07-08 21:01 ` [PATCH 06/18] fs_context: fix memory leak with 's' (source) command Eric Biggers
2018-07-08 21:01 ` [PATCH 07/18] fs_context: fix double free of legacy_fs_context data Eric Biggers
2018-07-08 21:01 ` [PATCH 08/18] fsmount: pass up error code from dentry_open() Eric Biggers
2018-07-08 21:01 ` [PATCH 09/18] fsmount: fix handling FSMOUNT_CLOEXEC Eric Biggers
2018-07-08 21:01 ` [PATCH 10/18] fsmount: fix bypassing SB_MANDLOCK permission check Eric Biggers
2018-07-08 21:01 ` [PATCH 11/18] fspick: fix path leak Eric Biggers
2018-07-08 21:01 ` [PATCH 12/18] fspick: add missing permission check Eric Biggers
2018-07-08 21:01 ` [PATCH 13/18] fsmount: removed unused variable 'inode' Eric Biggers
2018-07-08 21:01 ` [PATCH 14/18] fsopen,fspick: factor out log allocation Eric Biggers
2018-07-08 21:01 ` [PATCH 15/18] fsopen,fspick: rename fsopen_create_fd() to fscontext_create_fd() Eric Biggers
2018-07-08 21:01 ` Eric Biggers [this message]
2018-07-08 21:01 ` [PATCH 17/18] fs_context: de-obfuscate command validation Eric Biggers
2018-07-08 21:01 ` [PATCH 18/18] fs_context: fix fscontext_write() comment Eric Biggers
2018-07-08 23:46 ` [PATCH vfs/for-next 00/18] fs_context fixes Eric Biggers
2018-07-09  9:32 ` [PATCH 03/18] fs_context: fix detecting full log buffer David Howells
2018-07-09  9:35 ` David Howells
2018-07-09 12:31 ` [PATCH 07/18] fs_context: fix double free of legacy_fs_context data David Howells
2018-07-10  1:17   ` Eric Biggers
2018-07-10  1:25     ` Eric Biggers
2018-07-10  8:02   ` David Howells
2018-07-09 15:31 ` [PATCH vfs/for-next 00/18] fs_context fixes David Howells
2018-07-09 15:56   ` Al Viro
2018-07-09 16:28   ` David Howells
2018-07-09 21:57   ` David Howells

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