Messages in this thread | | | Date | Thu, 07 May 2015 19:24:08 -0400 | From | Peter Hurley <> | Subject | Re: [PATCH] devpts: If initialization failed, don't crash when opening /dev/ptmx |
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On 05/07/2015 06:59 PM, Andrew Morton wrote: > On Wed, 6 May 2015 17:35:47 -0700 Josh Triplett <josh@joshtriplett.org> wrote: > >> If devpts failed to initialize, it would store an ERR_PTR in the global >> devpts_mnt. A subsequent open of /dev/ptmx would call devpts_new_index, >> which would dereference devpts_mnt and crash. >> >> Avoid storing invalid values in devpts_mnt; leave it NULL instead. >> Make both devpts_new_index and devpts_pty_new fail gracefully with >> ENODEV in that case, which then becomes the return value to the >> userspace open call on /dev/ptmx. > > It looks like the system is pretty crippled if init_devptr_fs() fails. > Can the user actually get access to consoles and do useful things in > this situation? Maybe it would be better to just give up and panic?
A single-user console is definitely reachable without devpts. From there, one could fixup to a not-broken kernel.
Regards, Peter Hurley
PS - But I saw you already added these to -mm
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