On Fri, 2014-10-31 at 07:50 +0100, Greg Kurz wrote: > The add_early_randomness() function in drivers/char/hw_random/core.c passes > a 16-byte buffer to pseries_rng_data_read(). Unfortunately, plpar_hcall() > returns four 64-bit values and trashes 16 bytes on the stack.
Hmm, thanks. I thought I'd fixed that, but I guess I never sent the patch :} > This bug has been lying around for a long time. It got unveiled by: > > commit d3cc7996473a7bdd33256029988ea690754e4e2a > Author: Amit Shah <amit.s...@redhat.com> > Date: Thu Jul 10 15:42:34 2014 +0530 > > hwrng: fetch randomness only after device init > > It may trig a oops while loading or unloading the pseries-rng module for both > PowerVM and PowerKVM guests. > > This patch does two things: > - pass an intermediate well sized buffer to plpar_hcall(). This is acceptalbe > since we're not on a hot path. Well probably, can you do a before and after test of dd if=/dev/hwrng ? > Cc'ing stable as I could reproduce back to 3.15.10 The right way to CC stable for a patch that isn't yet in upstream is to add: CC: sta...@vger.kernel.org Before your Signed-off-by. They will then pick it up once it's merged into Linus' tree. See Documentation/stable_kernel_rules.txt cheers _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
