From: Bart Van Assche <bvanassche@acm.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Joel Becker <jlbec@evilplan.org>,
linux-kernel@vger.kernel.org,
Bodo Stroesser <bostroesser@gmail.com>,
"Martin K . Petersen" <martin.petersen@oracle.com>,
Yanko Kaneti <yaneti@declera.com>,
Brendan Higgins <brendanhiggins@google.com>,
Bart Van Assche <bvanassche@acm.org>
Subject: [PATCH 1/4] configfs: Rework the overflow check in fill_write_buffer()
Date: Fri, 23 Jul 2021 14:23:50 -0700 [thread overview]
Message-ID: <20210723212353.896343-2-bvanassche@acm.org> (raw)
In-Reply-To: <20210723212353.896343-1-bvanassche@acm.org>
Change 'if (SIMPLE_ATTR_SIZE - 1 - pos <= 0)' into
'if (pos >= SIMPLE_ATTR_SIZE - 1)'. Change the data type of 'to_copy'
from long long (loff_t) into int. Do not check whether pos < 0 since
rw_verify_area() checks this for us. As one can see on
https://lore.kernel.org/lkml/CAHk-=wjuDBQdUvaO=XaptgmvE_qeg_EuZjsUZf2vVoXPUMgAvg@mail.gmail.com/
these changes have been requested by Linus Torvalds.
Cc: Bodo Stroesser <bostroesser@gmail.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Yanko Kaneti <yaneti@declera.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
fs/configfs/file.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index 5a0be9985bae..8121bb1b2121 100644
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -181,8 +181,7 @@ static ssize_t configfs_bin_read_iter(struct kiocb *iocb, struct iov_iter *to)
static int fill_write_buffer(struct configfs_buffer *buffer, loff_t pos,
struct iov_iter *from)
{
- loff_t to_copy;
- int copied;
+ int to_copy, copied;
u8 *to;
if (!buffer->page)
@@ -190,9 +189,9 @@ static int fill_write_buffer(struct configfs_buffer *buffer, loff_t pos,
if (!buffer->page)
return -ENOMEM;
- to_copy = SIMPLE_ATTR_SIZE - 1 - pos;
- if (to_copy <= 0)
+ if (pos >= SIMPLE_ATTR_SIZE - 1)
return 0;
+ to_copy = SIMPLE_ATTR_SIZE - 1 - pos;
to = buffer->page + pos;
copied = copy_from_iter(to, to_copy, from);
buffer->needs_read_fill = 1;
next prev parent reply other threads:[~2021-07-23 21:24 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-23 21:23 [PATCH 0/4] Improve the configfs read and write iterators further Bart Van Assche
2021-07-23 21:23 ` Bart Van Assche [this message]
2021-07-23 21:23 ` [PATCH 2/4] configfs: Fix writing at a non-zero offset Bart Van Assche
2021-07-26 14:58 ` Bodo Stroesser
2021-07-26 16:26 ` Bart Van Assche
2021-07-26 21:13 ` Bodo Stroesser
2021-07-26 21:52 ` Bart Van Assche
2021-07-27 0:54 ` Bodo Stroesser
2021-07-27 3:17 ` Bart Van Assche
2021-07-27 7:27 ` Bodo Stroesser
2021-07-27 16:47 ` Bart Van Assche
2021-07-28 17:14 ` Bodo Stroesser
2021-07-28 17:55 ` Bart Van Assche
2021-07-23 21:23 ` [PATCH 3/4] kunit: Add support for suite initialization and cleanup Bart Van Assche
2021-07-27 21:26 ` Brendan Higgins
2021-07-29 3:33 ` Bart Van Assche
2021-07-23 21:23 ` [PATCH 4/4] configfs: Add unit tests Bart Van Assche
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