On 12-02-2024 13:25, Mika Westerberg wrote:
On Mon, Feb 12, 2024 at 01:15:18PM +0100, Olliver Schinagl wrote:
Hey Mika,
On 12-02-2024 12:51, Mika Westerberg wrote:
Olliver reported that his system crashes when plugging in Thunderbolt 1
device:
BUG: kernel NULL pointer dereference, address: 0000000000000020
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:tb_port_do_update_credits+0x1b/0x130 [thunderbolt]
Call Trace:
<TASK>
? __die+0x23/0x70
? page_fault_oops+0x171/0x4e0
? exc_page_fault+0x7f/0x180
? asm_exc_page_fault+0x26/0x30
? tb_port_do_update_credits+0x1b/0x130
? tb_switch_update_link_attributes+0x83/0xd0
tb_switch_add+0x7a2/0xfe0
tb_scan_port+0x236/0x6f0
tb_handle_hotplug+0x6db/0x900
process_one_work+0x171/0x340
worker_thread+0x27b/0x3a0
? __pfx_worker_thread+0x10/0x10
kthread+0xe5/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
This is due the fact that some Thunderbolt 1 devices only have one lane
adapter. Fix this by checking for the lane 1 before we read its credits.
Reported-by: Olliver Schinagl <oliver@xxxxxxxxxxx>
Closes: https://lore.kernel.org/linux-usb/c24c7882-6254-4e68-8f22-f3e8f65dc84f@xxxxxxxxxxx/
Fixes: 81af2952e606 ("thunderbolt: Add support for asymmetric link")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Gil Fine <gil.fine@xxxxxxxxxxxxxxx>
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
Hi Olliver,
I managed to reproduce this with a Thunderbolt 1 device. I wonder if you
can try this patch and see if it fixes your issue too?
That sounds reasonable, as it's an old Macbook (Should be TB2) with an old
ethernet dongle (probably TB1?) or simply because it doesn't need that much
speed (gbit adapter only). Sadly patching my kernel is not something I can
do at the moment.
Right, if you plug in a TB1 device into TB2 host, that's also same issue
(TB1 devices don't always have two lane adapters).
It's fine if you cannot test this (but let me know if you want
instructions). I can pick this into my fixes branch and send for -rc. It
should land the arch Linux kernel tree at some point too, so you get it
by upgrading the kernel.
Yeah, I'll gently wait for it to land there. I'm using a 10/100Mbit USB
adapter for those few times I need it :)
Thanks for looking into this!
Olliver
