Hi, On Fri, Aug 07, 2020 at 08:43:15AM -0700, Zwane Mwaikambo wrote: > This patch was posted previously on lkml. I've updated the patch to fix > another memory overrun in ucsi_unregister_altmodes Could you please give a link to the thread in lkml that you are referring to (from here: https://lore.kernel.org/lkml/)? This is not formated as a patch. It's not signed and the subject is not appropriate. Is this meant to be a bug report? If this is meant to be a patch, please prepare it according to the rules that are explained for example here: https://www.kernel.org/doc/html/latest/process/submitting-patches.html thanks, > The following crash occurs whilst plugging in a Thinkpad USB type C dock > and appears to be affecting other users as seen below; > > https://bbs.archlinux.org/viewtopic.php?id=256404 > https://forums.linuxmint.com/viewtopic.php?p=1826251 > > My specific crash is; > > [ 565.427757] input: USBPS2 as > /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.1/1-2.1.4/1-2.1.4:1.0/0003:0D3D:0001.0006/input/input31 > [ 565.452023] BUG: kernel NULL pointer dereference, address: 00000000000002fe > [ 565.452025] #PF: supervisor read access in kernel mode > [ 565.452026] #PF: error_code(0x0000) - not-present page > [ 565.452026] PGD 0 P4D 0 > [ 565.452028] Oops: 0000 [#1] PREEMPT SMP NOPTI > [ 565.452030] CPU: 0 PID: 502 Comm: kworker/0:3 Not tainted 5.8.0-rc3+ #1 > [ 565.452031] Hardware name: LENOVO 20RD002VUS/20RD002VUS, BIOS R16ET25W (1.11 ) 04/21/2020 > [ 565.452034] Workqueue: events ucsi_handle_connector_change [typec_ucsi] > [ 565.452039] RIP: 0010:typec_altmode_update_active+0x1f/0x100 [typec] > [ 565.452040] Code: 0f 1f 84 00 00 00 00 00 0f 1f 00 0f 1f 44 00 00 55 48 > 89 e5 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 45 e8 31 c0 > <0f> b6 87 fc 02 00 00 83 e0 01 40 38 f0 0f 84 95 00 00 00 48 8b 47 > [ 565.452041] RSP: 0018:ffffb729c066bdb0 EFLAGS: 00010246 > [ 565.452042] RAX: 0000000000000000 RBX: ffffa067c3e64a70 RCX: 0000000000000000 > [ 565.452043] RDX: ffffb729c066bd20 RSI: 0000000000000000 RDI: 0000000000000002 > [ 565.452044] RBP: ffffb729c066bdd0 R08: 00000083a7910a4f R09: 0000000000000000 > [ 565.452044] R10: ffffffffa106a220 R11: 0000000000000000 R12: 0000000000000000 > [ 565.452045] R13: ffffa067c3e64a98 R14: ffffa067c3e64810 R15: ffffa067c3e64800 > [ 565.452046] FS: 0000000000000000(0000) GS:ffffa067d1400000(0000) knlGS:0000000000000000 > [ 565.452047] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 565.452048] CR2: 00000000000002fe CR3: 00000001b060a003 CR4: 00000000003606f0 > [ 565.452048] Call Trace: > [ 565.452052] ucsi_altmode_update_active+0x83/0xd0 [typec_ucsi] > [ 565.452054] ucsi_handle_connector_change+0x1dc/0x320 [typec_ucsi] > [ 565.452057] process_one_work+0x1df/0x3d0 > [ 565.452059] worker_thread+0x4d/0x3d0 > [ 565.452060] ? process_one_work+0x3d0/0x3d0 > [ 565.452062] kthread+0x127/0x170 > [ 565.452063] ? kthread_park+0x90/0x90 > [ 565.452065] ret_from_fork+0x1f/0x30 > > The failing instruction is; > > 0x0000000000000380 <+0>: callq 0x385 <typec_altmode_update_active+5> > 0x0000000000000385 <+5>: push %rbp > 0x0000000000000386 <+6>: mov %rsp,%rbp > 0x0000000000000389 <+9>: push %r12 > 0x000000000000038b <+11>: push %rbx > 0x000000000000038c <+12>: sub $0x10,%rsp > 0x0000000000000390 <+16>: mov %gs:0x28,%rax > 0x0000000000000399 <+25>: mov %rax,-0x18(%rbp) > 0x000000000000039d <+29>: xor %eax,%eax > 0x000000000000039f <+31>: movzbl 0x2fc(%rdi),%eax <====== > 0x00000000000003a6 <+38>: and $0x1,%eax > > (gdb) list *typec_altmode_update_active+0x1f > 0x39f is in typec_altmode_update_active (drivers/usb/typec/class.c:221). > 216 */ > 217 void typec_altmode_update_active(struct typec_altmode *adev, bool active) > 218 { > 219 char dir[6]; > 220 > 221 if (adev->active == active) > 222 return; > 223 > 224 if (!is_typec_port(adev->dev.parent) && adev->dev.driver) { > 225 if (!active) > > (gdb) list *ucsi_altmode_update_active+0x83 > 0x12a3 is in ucsi_altmode_update_active (drivers/usb/typec/ucsi/ucsi.c:221). > 216 } > 217 > 218 if (cur < UCSI_MAX_ALTMODES) > 219 altmode = typec_altmode_get_partner(con->port_altmode[cur]); > 220 > 221 for (i = 0; con->partner_altmode[i]; i++) > 222 typec_altmode_update_active(con->partner_altmode[i], > 223 con->partner_altmode[i] == altmode); > 224 } > > con->partner_altmode[i] ends up with the value 0x2 in the call and it's > because the array has been accessed out of bounds. There is also another > occurence of this which shows up as the following crash; > > [ 4372.429633] usb 1-2.1.4: USB disconnect, device number 16 > [ 4372.523235] usb 1-2.2: USB disconnect, device number 7 > [ 4372.570537] usb 1-2.5: USB disconnect, device number 9 > [ 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 > > 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 > @@ -218,9 +218,10 @@ void ucsi_altmode_update_active(struct ucsi_connector *con) > if (cur < UCSI_MAX_ALTMODES) > altmode = typec_altmode_get_partner(con->port_altmode[cur]); > > - for (i = 0; con->partner_altmode[i]; i++) > - typec_altmode_update_active(con->partner_altmode[i], > - con->partner_altmode[i] == altmode); > + for (i = 0; i < UCSI_MAX_ALTMODES; i++) > + if (con->partner_altmode[i]) > + typec_altmode_update_active(con->partner_altmode[i], > + con->partner_altmode[i] == altmode); > } > > static u8 ucsi_altmode_next_mode(struct typec_altmode **alt, u16 svid) > @@ -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
