This is a note to let you know that I've just added the patch titled
iommu: iommufd: fix WARNING in iommufd_device_unbind
to the 6.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-iommufd-fix-warning-in-iommufd_device_unbind.patch
and it can be found in the queue-6.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cd8b56d4a331135e05cd94792bcb0b1222e779da
Author: Suraj Sonawane <surajsonawane0215@xxxxxxxxx>
Date: Sun Nov 24 01:29:00 2024 +0530
iommu: iommufd: fix WARNING in iommufd_device_unbind
[ Upstream commit d9df72c6acd683adf6dd23c061f3a414ec00b1f8 ]
Fix an issue detected by syzbot:
WARNING in iommufd_device_unbind iommufd: Time out waiting for iommufd object to become free
Resolve a warning in iommufd_device_unbind caused by a timeout while
waiting for the shortterm_users reference count to reach zero. The
existing 10-second timeout is insufficient in some scenarios, resulting in
failures the above warning.
Increase the timeout in iommufd_object_dec_wait_shortterm from 10 seconds
to 60 seconds to allow sufficient time for the reference count to drop to
zero. This change prevents premature timeouts and reduces the likelihood
of warnings during iommufd_device_unbind.
Fixes: 6f9c4d8c468c ("iommufd: Do not UAF during iommufd_put_object()")
Link: https://patch.msgid.link/r/20241123195900.3176-1-surajsonawane0215@xxxxxxxxx
Reported-by: syzbot+c92878e123785b1fa2db@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=c92878e123785b1fa2db
Tested-by: syzbot+c92878e123785b1fa2db@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Suraj Sonawane <surajsonawane0215@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index b5f5d27ee9634..649fe79d0f0cc 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -130,7 +130,7 @@ static int iommufd_object_dec_wait_shortterm(struct iommufd_ctx *ictx,
if (wait_event_timeout(ictx->destroy_wait,
refcount_read(&to_destroy->shortterm_users) ==
0,
- msecs_to_jiffies(10000)))
+ msecs_to_jiffies(60000)))
return 0;
pr_crit("Time out waiting for iommufd object to become free\n");
