From: Shannon Nelson Date: Fri, 25 Apr 2025 20:38:57 +0000 (-0700) Subject: pds_core: remove write-after-free of client_id X-Git-Tag: v6.15-rc5~22^2~17 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dfd76010f8e821b66116dec3c7d90dd2403d1396;p=thirdparty%2Flinux.git pds_core: remove write-after-free of client_id 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: 10659034c622 ("pds_core: add the aux client API") Signed-off-by: Shannon Nelson Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250425203857.71547-1-shannon.nelson@amd.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/amd/pds_core/auxbus.c b/drivers/net/ethernet/amd/pds_core/auxbus.c index c9aac27883a3c..92f359f2b4492 100644 --- a/drivers/net/ethernet/amd/pds_core/auxbus.c +++ b/drivers/net/ethernet/amd/pds_core/auxbus.c @@ -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);