From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B4889346AE1; Tue, 25 Aug 2026 01:54:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787622843; cv=none; b=MKmasRNBGhhHkzNZRcgw7ce8ku66OqZuYmKJfXfisz8JNWr5s8mdyBL3M+ls8aTeuCtxawtQdqQg2ChNjKr+gbGcesJpKptQm7HWVRXDvTsKGI6U5hyNBeUy/tRD15F5+VCNetcUQtEnagWSJXvjCgKOySHEbTuZDku069FBH/E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787622843; c=relaxed/simple; bh=pBdtcemevuwkSgQ7HfB/ZLJhIRDOKV4JmXMbaUvMzaQ=; h=Date:To:From:Subject:Message-Id; b=U2iGNevwJ4NCLPQNMCX8H+Z3DL8ESBLxBhmKTK6qjuqGgWE8R8FgoDyoL3roprE6Cp4wkNtszyLevUuX+qkwprq4BP8DaCzQDtA9CA2V3Q3A5yudqJmtB22LaBz7vPTJNJKRosrYfiMmRVaRt8VSubspWiGuAToBBdHq+w3TNQQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=imNeySJS; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="imNeySJS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 921051F000E9; Tue, 25 Aug 2026 01:54:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1787622841; bh=L5Xa/nquVif7gbdUEpPSNLYs8GemIMvG0yb4PKuZllE=; h=Date:To:From:Subject; b=imNeySJSnVSbM1NVVF5Afg7GZVK1O/FCZ4fFYAhAG88bPWutOTMor760q2Q0uJnq/ TCaAh5cZ1WgSTd8r/9DZxgQx/s8hiU+Du+/4VEb+Tn6nyT+LmCye/U32QCn+NraooQ snBvhEs8qbA/AriPHt0O9oCf/9ADa1xez7GEhyz8= Date: Mon, 24 Aug 2026 18:54:01 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,senozhatsky@chromium.org,minchan@kernel.org,axboe@kernel.dk,xialonglong@kylinos.cn,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] zram-fix-out-of-bounds-access-in-writeback_store.patch removed from -mm tree Message-Id: <20260825015401.921051F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: zram: fix out-of-bounds access in writeback_store() has been removed from the -mm tree. Its filename was zram-fix-out-of-bounds-access-in-writeback_store.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Longlong Xia Subject: zram: fix out-of-bounds access in writeback_store() Date: Tue, 4 Aug 2026 14:59:18 +0800 Patch series "zram: fix stale scan bounds after reinitialization". Both writeback_store() and read_block_state() derive their table scan bounds from zram->disksize before acquiring dev_lock. If the device is reset and reinitialized with a smaller disksize between that read and lock acquisition, the bound can describe the old table while the scan operates on the new one. This can lead to out-of-bounds slot accesses. Move both bound calculations under dev_lock so each bound remains consistent with the table throughout its scan. Keep the fixes separate because the affected interfaces originate from different commits and can be backported independently. This patch (of 2): writeback_store() calculates the table scan bounds before taking dev_lock. A reset followed by reconfiguration with a smaller disksize can therefore replace zram->table while writeback_store() is waiting for the lock. Once it acquires the lock, it sees an initialized device but scans the new table using the old upper bound, resulting in an out-of-bounds access. Calculate the number of pages while holding dev_lock so the scan bound matches the table protected by the lock. Link: https://lore.kernel.org/20260804065919.3970386-1-xialonglong2025@163.com Link: https://lore.kernel.org/20260804065919.3970386-2-xialonglong2025@163.com Fixes: a939888ec38b ("zram: support idle/huge page writeback") Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Longlong Xia Reviewed-by: Sergey Senozhatsky Cc: Jens Axboe Cc: Minchan Kim Cc: Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/block/zram/zram_drv.c~zram-fix-out-of-bounds-access-in-writeback_store +++ a/drivers/block/zram/zram_drv.c @@ -1235,8 +1235,8 @@ static ssize_t writeback_store(struct de const char *buf, size_t len) { struct zram *zram = dev_to_zram(dev); - u64 nr_pages = zram->disksize >> PAGE_SHIFT; - unsigned long lo = 0, hi = nr_pages; + u64 nr_pages; + unsigned long lo = 0, hi; struct zram_pp_ctl *pp_ctl = NULL; struct zram_wb_ctl *wb_ctl = NULL; char *args, *param, *val; @@ -1250,6 +1250,9 @@ static ssize_t writeback_store(struct de if (!zram->backing_dev) return -ENODEV; + nr_pages = zram->disksize >> PAGE_SHIFT; + hi = nr_pages; + pp_ctl = init_pp_ctl(); if (!pp_ctl) return -ENOMEM; _ Patches currently in -mm which might be from xialonglong@kylinos.cn are mm-hugetlb-keep-max_huge_pages-when-dissolving-surplus-folios.patch