korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-11 04:18:39 +08:00
Code Issues Packages Projects Releases Wiki Activity

dma: fix call order in dmam_free_coherent

Browse Source 
[ Upstream commit 28e8b7406d ]

dmam_free_coherent() frees a DMA allocation, which makes the
freed vaddr available for reuse, then calls devres_destroy()
to remove and free the data structure used to track the DMA
allocation. Between the two calls, it is possible for a
concurrent task to make an allocation with the same vaddr
and add it to the devres list.

If this happens, there will be two entries in the devres list
with the same vaddr and devres_destroy() can free the wrong
entry, triggering the WARN_ON() in dmam_match.

Fix by destroying the devres entry before freeing the DMA
allocation.

Tested:
  kokonut //net/encryption
    http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03

Fixes: 9ac7849e35 ("devres: device resource management")
Signed-off-by: Lance Richardson <rlance@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Lance Richardson 2024-07-18 14:38:24 +00:00 committed by Greg Kroah-Hartman
parent 1c939f9457
commit 22094f5f52
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/dma/mapping.c
View File

@ -67,8 +67,8 @@ void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
{
struct dma_devres match_data = { size, vaddr, dma_handle };
dma_free_coherent(dev, size, vaddr, dma_handle);
WARN_ON(devres_destroy(dev, dmam_release, dmam_match, &match_data));
dma_free_coherent(dev, size, vaddr, dma_handle);
}
EXPORT_SYMBOL(dmam_free_coherent);