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From: Yi Sun <yi.sun@intel.com>
To: vinicius.gomes@intel.com, dmaengine@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: yi.sun@intel.com, gordon.jin@intel.com
Subject: [PATCH v2 0/2] dmaengine: idxd: Fix refcount and cleanup issues on module unload
Date: Sat,  7 Jun 2025 21:06:14 +0800	[thread overview]
Message-ID: <20250607130616.514984-1-yi.sun@intel.com> (raw)

This patch series addresses two issues related to the device reference
counting and cleanup path in the idxd driver.

Recent changes introduced improper put_device() calls and duplicated
cleanup logic, leading to refcount underflow and potential use-after-free
during module unload.

Patch 1 removes an unnecessary call to idxd_free(), which could result in a
use-after-free when paired with asynchronous put_device().

Patch 2 refactors the cleanup path to avoid redundant put_device() calls
introduced in commit a409e919ca3. The existing idxd_unregister_devices()
already handles proper device reference release.

Both patches have been verified on hardware platform.

Both patches have been run through `checkpatch.pl`. Patch 2 gets 1 error
and 1 warning. But these appear to be limitations in the checkpatch script
itself, not reflect issues with the patches.

---
Changes in v2:
- Reworded commit messages supplementing the call traces (Vinicius)
- Explain why the put_device are unnecessary. (Vinicius)

Yi Sun (2):
  dmaengine: idxd: Remove improper idxd_free
  dmaengine: idxd: Fix refcount underflow on module unload

 drivers/dma/idxd/init.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

-- 
2.43.0


             reply	other threads:[~2025-06-07 13:06 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-07 13:06 Yi Sun [this message]
2025-06-07 13:06 ` [PATCH v2 1/2] dmaengine: idxd: Remove improper idxd_free Yi Sun
2025-06-07 13:06 ` [PATCH v2 2/2] dmaengine: idxd: Fix refcount underflow on module unload Yi Sun
2025-06-13 23:20   ` Vinicius Costa Gomes
2025-06-14  7:13     ` Yi Sun

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