From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- drivers/md/bcache/request.h | 47 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 drivers/md/bcache/request.h (limited to 'drivers/md/bcache/request.h') diff --git a/drivers/md/bcache/request.h b/drivers/md/bcache/request.h new file mode 100644 index 000000000..46bbef00a --- /dev/null +++ b/drivers/md/bcache/request.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHE_REQUEST_H_ +#define _BCACHE_REQUEST_H_ + +struct data_insert_op { + struct closure cl; + struct cache_set *c; + struct bio *bio; + struct workqueue_struct *wq; + + unsigned int inode; + uint16_t write_point; + uint16_t write_prio; + blk_status_t status; + + union { + uint16_t flags; + + struct { + unsigned int bypass:1; + unsigned int writeback:1; + unsigned int flush_journal:1; + unsigned int csum:1; + + unsigned int replace:1; + unsigned int replace_collision:1; + + unsigned int insert_data_done:1; + }; + }; + + struct keylist insert_keys; + BKEY_PADDED(replace_key); +}; + +unsigned int bch_get_congested(const struct cache_set *c); +CLOSURE_CALLBACK(bch_data_insert); + +void bch_cached_dev_request_init(struct cached_dev *dc); +void cached_dev_submit_bio(struct bio *bio); + +void bch_flash_dev_request_init(struct bcache_device *d); +void flash_dev_submit_bio(struct bio *bio); + +extern struct kmem_cache *bch_search_cache; + +#endif /* _BCACHE_REQUEST_H_ */ -- cgit v1.3.1