ACPI: PCI: Clear driver_data on all paths that free the acpi_pci_root

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acpi_pci_root_add() assigns the freshly allocated root to
device->driver_data before dmar_device_add() and pci_acpi_scan_root().
Both failure paths reach the end: label where root is kfree()'d, but
only the pci_acpi_scan_root() path clears driver_data first.

When dmar_device_add() fails during a hot-add, root is freed while
device->driver_data still points at it.  The ACPI core does not clear
driver_data on attach failure, so a later acpi_pci_find_root() call may
dereference this dangling pointer.

acpi_pci_root_remove() has the same problem: it frees root without
clearing device->driver_data, leaving a dangling pointer behind after
the root bridge is removed.

Move the NULL assignment to the shared end: label so every error path in
acpi_pci_root_add() clears driver_data before freeing root, and clear it
in acpi_pci_root_remove() as well, so the object is never left reachable
through driver_data after being freed.

Fixes: db89b4f0db ("ACPI: catch calls of acpi_driver_data on pointer of wrong type")
Reported-by: Sashiko AI review <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260526025118.38935-1-cp0613@linux.alibaba.com
Link: https://sashiko.dev/#/patchset/20260707121258.11640-1-cp0613@linux.alibaba.com
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Link: https://patch.msgid.link/20260715135048.3278-1-cp0613@linux.alibaba.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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Chen Pei 2026-07-15 21:50:48 +08:00 • committed by Rafael J. Wysocki

parent 1590cf0329

commit 8a742141f7

1 changed files with 2 additions and 1 deletions

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drivers/acpi/pci_root.c

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