On Thu, Aug 27, 2020 at 11:35:53AM -0700, Zwane Mwaikambo wrote: > This fixes the second array overrun occurrence (similar failure mode to > the first), this time in ucsi_unregister_altmodes. > > [ 4373.153246] BUG: kernel NULL pointer dereference, address: > 00000000000002f2 > [ 4373.153267] #PF: supervisor read access in kernel mode > [ 4373.153271] #PF: error_code(0x0000) - not-present page > [ 4373.153275] PGD 0 P4D 0 > [ 4373.153284] Oops: 0000 [#2] PREEMPT SMP NOPTI > [ 4373.153292] CPU: 0 PID: 13242 Comm: kworker/0:0 Tainted: G D > 5.8.0-rc6+ #1 > [ 4373.153296] Hardware name: LENOVO 20RD002VUS/20RD002VUS, BIOS R16ET25W > (1.11 ) 04/21/2020 > [ 4373.153308] Workqueue: events ucsi_handle_connector_change [typec_ucsi] > [ 4373.153320] RIP: 0010:ucsi_unregister_altmodes+0x5f/0xa0 [typec_ucsi] > [ 4373.153326] Code: 54 48 8b 3b 41 83 c4 01 e8 9e f9 0c 00 49 63 c4 48 c7 > 03 00 00 00 00 49 8d 5c c5 00 48 8b 3b 48 85 ff 74 31 41 80 fe 01 75 d7 > <0f> b7 87 f0 02 00 00 66 3d 01 ff 74 0f 66 3d 55 09 75 c4 83 bf f8 > [ 4373.153332] RSP: 0018:ffffb2ef036b3dc8 EFLAGS: 00010246 > [ 4373.153338] RAX: 000000000000001e RBX: ffff94268b006a60 RCX: > 0000000080800067 > [ 4373.153342] RDX: 0000000080800068 RSI: 0000000000000001 RDI: > 0000000000000002 > [ 4373.153347] RBP: ffffb2ef036b3de8 R08: 0000000000000000 R09: > ffffffff8dc65400 > [ 4373.153351] R10: ffff9426678d7200 R11: 0000000000000001 R12: > 000000000000001e > [ 4373.153355] R13: ffff94268b006970 R14: 0000000000000001 R15: > ffff94268b006800 > [ 4373.153361] FS: 0000000000000000(0000) GS:ffff942691400000(0000) > knlGS:0000000000000000 > [ 4373.153366] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 4373.153371] CR2: 00000000000002f2 CR3: 00000004445a6005 CR4: > 00000000003606f0 > [ 4373.153375] Call Trace: > [ 4373.153389] ucsi_unregister_partner.part.0+0x17/0x30 [typec_ucsi] > [ 4373.153400] ucsi_handle_connector_change+0x25c/0x320 [typec_ucsi] > [ 4373.153418] process_one_work+0x1df/0x3d0 > [ 4373.153428] worker_thread+0x4a/0x3d0 > [ 4373.153436] ? process_one_work+0x3d0/0x3d0 > [ 4373.153444] kthread+0x127/0x170 > [ 4373.153451] ? kthread_park+0x90/0x90 > [ 4373.153461] ret_from_fork+0x1f/0x30 > [ 4373.153661] CR2: 00000000000002f2 > > Signed-off-by: Zwane Mwaikambo <zwane@xxxxxxxxx> This is also fixing something. Fixes: ad74b8649bea ("usb: typec: ucsi: Preliminary support for alternate modes") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Zwane Mwaikambo <zwane@xxxxxxxxx> > --- > > This v4 addresses patch formatting and submission issues with the > previous versions. > > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c > index d0c63afaf..79061705e 100644 > --- a/drivers/usb/typec/ucsi/ucsi.c > +++ b/drivers/usb/typec/ucsi/ucsi.c > @@ -479,7 +480,10 @@ static void ucsi_unregister_altmodes(struct ucsi_connector *con, u8 recipient) > return; > } > > - while (adev[i]) { > + for (i = 0; i < UCSI_MAX_ALTMODES; i++) { > + if (!adev[i]) > + break; > + > if (recipient == UCSI_RECIPIENT_SOP && > (adev[i]->svid == USB_TYPEC_DP_SID || > (adev[i]->svid == USB_TYPEC_NVIDIA_VLINK_SID && > @@ -488,7 +492,7 @@ static void ucsi_unregister_altmodes(struct ucsi_connector *con, u8 recipient) > ucsi_displayport_remove_partner((void *)pdev); > } > typec_unregister_altmode(adev[i]); > - adev[i++] = NULL; > + adev[i] = NULL; > } > } > -- heikki