On Mon, Feb 12, 2024 at 01:51:32PM +0200, 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> Applied to thunderbolt.git/fixes.
