diff options
| author | Yi Sun <yi.sun@intel.com> | 2025-07-29 23:03:12 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-19 16:37:38 +0200 |
| commit | da4fbc1488a4cec6748da685181ee4449a878dac (patch) | |
| tree | 2e3bb658ab8d18ade0586d1403be825fd98c8882 | |
| parent | a5f293d3931aaa709d7fa84be1bfeff11b992a04 (diff) | |
dmaengine: idxd: Remove improper idxd_free
[ Upstream commit f41c538881eec4dcf5961a242097d447f848cda6 ]
The call to idxd_free() introduces a duplicate put_device() leading to a
reference count underflow:
refcount_t: underflow; use-after-free.
WARNING: CPU: 15 PID: 4428 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110
...
Call Trace:
<TASK>
idxd_remove+0xe4/0x120 [idxd]
pci_device_remove+0x3f/0xb0
device_release_driver_internal+0x197/0x200
driver_detach+0x48/0x90
bus_remove_driver+0x74/0xf0
pci_unregister_driver+0x2e/0xb0
idxd_exit_module+0x34/0x7a0 [idxd]
__do_sys_delete_module.constprop.0+0x183/0x280
do_syscall_64+0x54/0xd70
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The idxd_unregister_devices() which is invoked at the very beginning of
idxd_remove(), already takes care of the necessary put_device() through the
following call path:
idxd_unregister_devices() -> device_unregister() -> put_device()
In addition, when CONFIG_DEBUG_KOBJECT_RELEASE is enabled, put_device() may
trigger asynchronous cleanup via schedule_delayed_work(). If idxd_free() is
called immediately after, it can result in a use-after-free.
Remove the improper idxd_free() to avoid both the refcount underflow and
potential memory corruption during module unload.
Fixes: d5449ff1b04d ("dmaengine: idxd: Add missing idxd cleanup to fix memory leak in remove call")
Signed-off-by: Yi Sun <yi.sun@intel.com>
Tested-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Link: https://lore.kernel.org/r/20250729150313.1934101-2-yi.sun@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/dma/idxd/init.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index 80355d03004d..40cc9c070081 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -1295,7 +1295,6 @@ static void idxd_remove(struct pci_dev *pdev) idxd_cleanup(idxd); pci_iounmap(pdev, idxd->reg_base); put_device(idxd_confdev(idxd)); - idxd_free(idxd); pci_disable_device(pdev); } |