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From: Kairui Song <ryncsn@gmail.com>
To: linux-mm@kvack.org
Cc: Minchan Kim <minchan@kernel.org>,
	Sergey Senozhatsky <senozhatsky@chromium.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	Kairui Song <kasong@tencent.com>,
	stable@vger.kernel.org
Subject: [PATCH] zram: fix potential UAF of zram table
Date: Tue,  7 Jan 2025 14:54:46 +0800	[thread overview]
Message-ID: <20250107065446.86928-1-ryncsn@gmail.com> (raw)

From: Kairui Song <kasong@tencent.com>

If zram_meta_alloc failed early, it frees allocated zram->table without
setting it NULL. Which will potentially cause zram_meta_free to access
the table if user reset an failed and uninitialized device.

Fixes: 74363ec674cb ("zram: fix uninitialized ZRAM not releasing backing device")
Cc: <stable@vger.kernel.org>
Signed-off-by: Kairui Song <kasong@tencent.com>
---
 drivers/block/zram/zram_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 5b8e4f4171ab..70ecaee25c20 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1465,6 +1465,7 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize)
 	zram->mem_pool = zs_create_pool(zram->disk->disk_name);
 	if (!zram->mem_pool) {
 		vfree(zram->table);
+		zram->table = NULL;
 		return false;
 	}
 
-- 
2.47.1



             reply	other threads:[~2025-01-07  6:55 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-07  6:54 Kairui Song [this message]
2025-01-07  7:38 ` Sergey Senozhatsky

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