From 1b1a4e4d6797a57fefa40569fc920ce573bbf75b Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Sat, 22 Nov 2025 16:40:29 +0900 Subject: [PATCH] zram: read slot block idx under slot lock Read slot's block id under slot-lock. We release the slot-lock for bdev read so, technically, slot still can get freed in the meantime, but at least we will read bdev block (page) that holds previous know slot data, not from slot->handle bdev block, which can be anything at that point. Link: https://lkml.kernel.org/r/20251122074029.3948921-7-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Cc: Brian Geffon Cc: Minchan Kim Cc: Richard Chang Cc: Yuwen Chen Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 1f7e9e914d345..3428f647d0a75 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1995,14 +1995,14 @@ static int zram_read_page(struct zram *zram, struct page *page, u32 index, ret = zram_read_from_zspool(zram, page, index); zram_slot_unlock(zram, index); } else { + unsigned long blk_idx = zram_get_handle(zram, index); + /* * The slot should be unlocked before reading from the backing * device. */ zram_slot_unlock(zram, index); - - ret = read_from_bdev(zram, page, zram_get_handle(zram, index), - parent); + ret = read_from_bdev(zram, page, blk_idx, parent); } /* Should NEVER happen. Return bio error if it does. */ -- 2.47.3