Hello, Matthias Reichl, le mer. 04 nov. 2020 15:57:37 +0100, a ecrit: > I initially noticed this oops on x86_64 running kernel 5.4.59 when > I accidentally mistyped "ttyS0" as "ttyS9": > > modprobe speakup_dummy dev=ttyS9 > [ 49.978481] tty_init_dev: ttyS driver does not set tty->port. This would crash the kernel. Fix the driver! This looks like only a warning, did it actually crash? > the missing tty->port is quite fatal. It is fatal for module insertion yes (EINVAL) but IIRC that should be getting handled properly, making modprobe return the error? > It looks like spk_ttyio or tty_dev_name_to_number() / tty_kopen() > should perform some additional validation, spk_ttyio_initialise_ldisc only has a dev_t so can't do much beyond calling tty_kopen. tty_kopen is getting the index from the tty_lookup_driver call (actually get_tty_driver which uses p->minor_start and p->num) and passes it to tty_driver_lookup_tty. Perhaps in addition of p->num the driver should have another field to set, that tty_init_dev could use to reject with ENODEV indexes beyond what the driver actually provides? > I couldn't make the kernel warn/crash yet by specifying non-existent > ttyUSB ports yet though. That's probably because in the ttyUSB case the device allocation is dynamic and made exactly according to the number of actual devices, while for ttyS* there is a large overcommit of minor values. Samuel
