+ zram-reject-zero-size-dictionary.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: zram: reject zero-size dictionary
has been added to the -mm mm-new branch.  Its filename is
     zram-reject-zero-size-dictionary.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-reject-zero-size-dictionary.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Haoqin Huang <haoqinhuang@tencent.com>
Subject: zram: reject zero-size dictionary
Date: Tue, 4 Aug 2026 17:38:38 +0800

kernel_read_file_from_path() already rejects empty files (i_size <= 0) and
returns -EINVAL, but the current implementation only checks for sz < 0
without logging any information.  Use sz == 0 to reject the zero-size case
and print distinct error messages for each failure type.

Link: https://lore.kernel.org/20260804093841.67920-3-haoqinhuang7@gmail.com
Signed-off-by: Haoqin Huang <haoqinhuang@tencent.com>
Signed-off-by: Rongwei Wang <zigiwang@tencent.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/block/zram/zram_drv.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/block/zram/zram_drv.c~zram-reject-zero-size-dictionary
+++ a/drivers/block/zram/zram_drv.c
@@ -1700,8 +1700,16 @@ static int comp_params_store(struct zram
 						INT_MAX,
 						NULL,
 						READING_POLICY);
-		if (sz < 0)
+		if (sz < 0) {
+			pr_err("failed to load dictionary %s (err=%zd)\n",
+			       dict_path, sz);
+			return sz;
+		}
+		if (sz == 0) {
+			pr_err("failed to load dictionary %s (empty file)\n",
+			       dict_path);
 			return -EINVAL;
+		}
 	}
 
 	zram->params[prio].dict_sz = sz;
_

Patches currently in -mm which might be from haoqinhuang@tencent.com are

zram-do-not-release-zstd-global-params-from-error-paths.patch
zram-reject-zero-size-dictionary.patch
zram-add-pr_fmt-to-backend-files.patch
zram-validate-parameters-in-each-backends-setup_params.patch
zram-reset-per-priority-params-when-changing-algorithm-before-init.patch