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| author | Ira Weiny <ira.weiny@intel.com> | 2026-03-06 12:33:05 -0600 |
|---|---|---|
| committer | Ira Weiny <ira.weiny@intel.com> | 2026-03-09 09:38:22 -0500 |
| commit | a8aec14230322ed8f1e8042b6d656c1631d41163 (patch) | |
| tree | 341bcd8879435c31c787856d97ac163ff5c624a3 /drivers/nvdimm | |
| parent | 1f318b96cc84d7c2ab792fcc0bfd42a7ca890681 (diff) | |
| download | lwn-a8aec14230322ed8f1e8042b6d656c1631d41163.tar.gz lwn-a8aec14230322ed8f1e8042b6d656c1631d41163.zip | |
nvdimm/bus: Fix potential use after free in asynchronous initialization
Dingisoul with KASAN reports a use after free if device_add() fails in
nd_async_device_register().
Commit b6eae0f61db2 ("libnvdimm: Hold reference on parent while
scheduling async init") correctly added a reference on the parent device
to be held until asynchronous initialization was complete. However, if
device_add() results in an allocation failure the ref count of the
device drops to 0 prior to the parent pointer being accessed. Thus
resulting in use after free.
The bug bot AI correctly identified the fix. Save a reference to the
parent pointer to be used to drop the parent reference regardless of the
outcome of device_add().
Reported-by: Dingisoul <dingiso.kernel@gmail.com>
Closes: http://lore.kernel.org/8855544b-be9e-4153-aa55-0bc328b13733@gmail.com
Fixes: b6eae0f61db2 ("libnvdimm: Hold reference on parent while scheduling async init")
Cc: stable@vger.kernel.org
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260306-fix-uaf-async-init-v1-1-a28fd7526723@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Diffstat (limited to 'drivers/nvdimm')
| -rw-r--r-- | drivers/nvdimm/bus.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index bd9621d3f73c..45b7d756e39a 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -486,14 +486,15 @@ EXPORT_SYMBOL_GPL(nd_synchronize); static void nd_async_device_register(void *d, async_cookie_t cookie) { struct device *dev = d; + struct device *parent = dev->parent; if (device_add(dev) != 0) { dev_err(dev, "%s: failed\n", __func__); put_device(dev); } put_device(dev); - if (dev->parent) - put_device(dev->parent); + if (parent) + put_device(parent); } static void nd_async_device_unregister(void *d, async_cookie_t cookie) |