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.
next prev 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
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