The Linux Kernel Mailing List
 help / color / mirror / Atom feed
From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Haoqin Huang <haoqinhuang7@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>,
	 Sergey Senozhatsky <senozhatsky@chromium.org>,
	Jens Axboe <axboe@kernel.dk>, Nick Terrell <terrelln@fb.com>,
	 David Sterba <dsterba@suse.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	 linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
	 Haoqin Huang <haoqinhuang@tencent.com>,
	Rongwei Wang <zigiwang@tencent.com>
Subject: Re: [PATCH v2 1/5] zram: fix early release of global cdict/ddict in per-CPU error path
Date: Wed, 29 Jul 2026 11:20:20 +0900	[thread overview]
Message-ID: <amljC3jQduwortXG@google.com> (raw)
In-Reply-To: <20260728092935.31139-1-haoqinhuang7@gmail.com>

On (26/07/28 17:29), Haoqin Huang wrote:
> zstd_setup_params() creates global cdict and ddict stored in
> params->drv_data, shared across all per-CPU contexts. The per-CPU
> zstd_create() error path called zstd_release_params(), which freed
> those globally-shared objects. While the drv_data=NULL guard in
> zstd_release_params() prevents a double-free on the init failure
> path, this is still a layering violation: a per-CPU callback should
> only clean up its own context, not release resources owned by the
> compression lifecycle (zcomp_init / zcomp_destroy).
> 
> Fix by removing zstd_release_params() from the per-CPU error path
> and replacing it with only zstd_destroy(), which properly cleans
> up the per-CPU context without touching the global params->drv_data.
> 
> Fixes: 6a559ecd6e7e ("zram: add dictionary support to zstd backend")

As we agreed earlier, this patch doesn't fix any known issues per se.
Let's not send a false signal to stable folks that this patch is
fixing a bug, let's not add Fixes: where they don't belong.

  parent reply	other threads:[~2026-07-29  2:20 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-27  7:02 [PATCH 1/3] zram: fix zstd dict use-after-free on per-CPU error path Haoqin Huang
2026-06-27  7:02 ` [PATCH 2/3] zram: add per-backend capability flags and validate parameters early Haoqin Huang
2026-07-24  5:27   ` Sergey Senozhatsky
2026-07-27 16:50     ` haoqin huang
2026-07-28  1:19       ` Sergey Senozhatsky
2026-07-28  9:07         ` haoqin huang
2026-07-28  1:27   ` Sergey Senozhatsky
2026-07-28  9:09     ` haoqin huang
2026-06-27  7:02 ` [PATCH 3/3] zram: reset per-priority params when changing algorithm before init Haoqin Huang
2026-07-24  5:19   ` Sergey Senozhatsky
2026-07-07  7:19 ` [PATCH 1/3] zram: fix zstd dict use-after-free on per-CPU error path Sergey Senozhatsky
2026-07-24  5:17 ` Sergey Senozhatsky
2026-07-27 16:06   ` haoqin huang
2026-07-28  1:21     ` Sergey Senozhatsky
2026-07-28  9:29 ` [PATCH v2 1/5] zram: fix early release of global cdict/ddict in " Haoqin Huang
2026-07-28  9:29   ` [PATCH v2 2/5] zram: make dict update in comp_params_store() atomic Haoqin Huang
2026-07-29  2:30     ` Sergey Senozhatsky
2026-07-29  4:06       ` haoqin huang
2026-07-29  4:16         ` Sergey Senozhatsky
2026-07-29  4:25           ` haoqin huang
2026-07-28  9:29   ` [PATCH v2 3/5] zstd: move ZSTD_MAX_CLEVEL to zstd_lib.h Haoqin Huang
2026-07-29  3:03     ` Sergey Senozhatsky
2026-07-29  4:16       ` haoqin huang
2026-07-29  4:22         ` Sergey Senozhatsky
2026-07-29  4:32           ` haoqin huang
2026-07-29  4:49             ` Sergey Senozhatsky
2026-07-28  9:29   ` [PATCH v2 4/5] zram: add per-backend caps and validate parameters early Haoqin Huang
2026-07-29  2:26     ` Sergey Senozhatsky
2026-07-29  3:53       ` haoqin huang
2026-07-28  9:29   ` [PATCH v2 5/5] zram: reset per-priority params when changing algorithm before init Haoqin Huang
2026-07-29  0:34   ` [PATCH v2 1/5] zram: fix early release of global cdict/ddict in per-CPU error path Andrew Morton
2026-07-29  2:49     ` Sergey Senozhatsky
2026-07-29  3:33     ` haoqin huang
2026-07-29  2:20   ` Sergey Senozhatsky [this message]
2026-07-29  3:40     ` haoqin huang
2026-07-29  2:40   ` Sergey Senozhatsky

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=amljC3jQduwortXG@google.com \
    --to=senozhatsky@chromium.org \
    --cc=akpm@linux-foundation.org \
    --cc=axboe@kernel.dk \
    --cc=dsterba@suse.com \
    --cc=haoqinhuang7@gmail.com \
    --cc=haoqinhuang@tencent.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=minchan@kernel.org \
    --cc=terrelln@fb.com \
    --cc=zigiwang@tencent.com \
    /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