From: Eric Sandeen <sandeen@sandeen.net>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 07/10] libxfs: refactor buffer item release code
Date: Mon, 22 Apr 2019 16:26:58 -0500 [thread overview]
Message-ID: <e964dcb8-5a9d-26bf-e5ac-7489c9f259a1@sandeen.net> (raw)
In-Reply-To: <155594793429.115924.9115512760848857551.stgit@magnolia>
On 4/22/19 10:45 AM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> Refactor the buffer item release code into a helper, which we will use
> in subsequent patches to make the buffer log item lifetime match the
> kernel equivalents.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> libxfs/trans.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
>
> diff --git a/libxfs/trans.c b/libxfs/trans.c
> index 9de77c8b..629501f8 100644
> --- a/libxfs/trans.c
> +++ b/libxfs/trans.c
> @@ -505,6 +505,16 @@ libxfs_trans_ordered_buf(
> return ret;
> }
>
> +static void
> +xfs_buf_item_put(
> + struct xfs_buf_log_item *bip)
> +{
> + struct xfs_buf *bp = bip->bli_buf;
> +
> + bp->b_log_item = NULL;
> + kmem_zone_free(xfs_buf_item_zone, bip);
> +}
> +
> void
> libxfs_trans_brelse(
> xfs_trans_t *tp,
> @@ -846,7 +856,6 @@ buf_item_done(
>
> bp = bip->bli_buf;
> ASSERT(bp != NULL);
> - bp->b_log_item = NULL; /* remove log item */
> bp->b_transp = NULL; /* remove xact ptr */
>
> hold = (bip->bli_flags & XFS_BLI_HOLD);
> @@ -861,8 +870,7 @@ buf_item_done(
> bip->bli_flags &= ~XFS_BLI_HOLD;
> else
> libxfs_putbuf(bp);
> - /* release the buf item */
> - kmem_zone_free(xfs_buf_item_zone, bip);
> + xfs_buf_item_put(bip);
In xfs_buf_item_put(), we reach back up from bip to bip->bli_buf, which is
the bp. This is after we did a libxfs_putbuf(bp) on that bp. Is there not
a chance of use after free here? Enough puts and a shaker can run, right?
> }
>
> static void
>
next prev parent reply other threads:[~2019-04-22 21:27 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-22 15:44 [PATCH v3 00/10] xfsprogs-5.0: fix various problems Darrick J. Wong
2019-04-22 15:44 ` [PATCH 01/10] scrub: fix Makefile targets which depend on builddefs Darrick J. Wong
2019-04-22 18:27 ` Eric Sandeen
2019-04-22 18:28 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 02/10] xfs_info: use findmnt to handle mounted block devices Darrick J. Wong
2019-04-22 18:35 ` Eric Sandeen
2019-04-22 19:27 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 03/10] xfs_repair: correctly account for free space btree shrinks when fixing freelist Darrick J. Wong
2019-04-22 19:24 ` Eric Sandeen
2019-04-22 19:36 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 04/10] libxfs: retain ifork_ops when flushing inode Darrick J. Wong
2019-04-22 19:40 ` Bill O'Donnell
2019-04-22 19:45 ` Eric Sandeen
2019-10-02 6:00 ` Arkadiusz Miśkiewicz
2019-04-22 15:45 ` [PATCH 05/10] libxfs: drop the ifork_ops parameter from _inode_verify_forks Darrick J. Wong
2019-04-22 19:43 ` Bill O'Donnell
2019-04-22 20:49 ` Eric Sandeen
2019-04-22 15:45 ` [PATCH 06/10] misc: fix strncpy length complaints Darrick J. Wong
2019-04-22 20:48 ` Eric Sandeen
2019-04-22 20:57 ` Darrick J. Wong
2019-04-22 21:04 ` Eric Sandeen
2019-04-22 21:07 ` Eric Sandeen
2019-04-23 15:07 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 07/10] libxfs: refactor buffer item release code Darrick J. Wong
2019-04-22 21:26 ` Eric Sandeen [this message]
2019-04-22 21:35 ` Darrick J. Wong
2019-04-22 21:40 ` Eric Sandeen
2019-04-23 20:51 ` [PATCH v2 " Darrick J. Wong
2019-04-23 20:56 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 08/10] libxfs: don't touch buffer log item pointer when flushing inode log item Darrick J. Wong
2019-04-23 17:56 ` Eric Sandeen
2019-04-23 20:52 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 09/10] libxfs: fix buffer log item lifetime weirdness Darrick J. Wong
2019-04-23 21:15 ` Bill O'Donnell
2019-04-22 15:45 ` [PATCH 10/10] libxfs: shorten inode item lifetime Darrick J. Wong
2019-04-23 21:22 ` Bill O'Donnell
2019-04-23 21:04 ` [PATCH 11/10] libfrog: fix memory leak in bitmap_free Darrick J. Wong
2019-04-23 21:23 ` Bill O'Donnell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=e964dcb8-5a9d-26bf-e5ac-7489c9f259a1@sandeen.net \
--to=sandeen@sandeen.net \
--cc=darrick.wong@oracle.com \
--cc=linux-xfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).