pds_core: remove write-after-free of client_id

[ Upstream commit dfd76010f8e821b66116dec3c7d90dd2403d1396 ]

A use-after-free error popped up in stress testing:

[Mon Apr 21 21:21:33 2025] BUG: KFENCE: use-after-free write in pdsc_auxbus_dev_del+0xef/0x160 [pds_core]
[Mon Apr 21 21:21:33 2025] Use-after-free write at 0x000000007013ecd1 (in kfence-#47):
[Mon Apr 21 21:21:33 2025]  pdsc_auxbus_dev_del+0xef/0x160 [pds_core]
[Mon Apr 21 21:21:33 2025]  pdsc_remove+0xc0/0x1b0 [pds_core]
[Mon Apr 21 21:21:33 2025]  pci_device_remove+0x24/0x70
[Mon Apr 21 21:21:33 2025]  device_release_driver_internal+0x11f/0x180
[Mon Apr 21 21:21:33 2025]  driver_detach+0x45/0x80
[Mon Apr 21 21:21:33 2025]  bus_remove_driver+0x83/0xe0
[Mon Apr 21 21:21:33 2025]  pci_unregister_driver+0x1a/0x80

The actual device uninit usually happens on a separate thread
scheduled after this code runs, but there is no guarantee of order
of thread execution, so this could be a problem.  There's no
actual need to clear the client_id at this point, so simply
remove the offending code.

Fixes: 10659034c6 ("pds_core: add the aux client API")
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250425203857.71547-1-shannon.nelson@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Shannon Nelson
2025-04-25 13:38:57 -07:00
committed by Greg Kroah-Hartman
parent 0861fccd43
commit 9b467c5bcd

View File

@@ -186,7 +186,6 @@ void pdsc_auxbus_dev_del(struct pdsc *cf, struct pdsc *pf,
pds_client_unregister(pf, padev->client_id);
auxiliary_device_delete(&padev->aux_dev);
auxiliary_device_uninit(&padev->aux_dev);
padev->client_id = 0;
*pd_ptr = NULL;
mutex_unlock(&pf->config_lock);