On Tue, Mar 20, 2018 at 10:48:48AM +0100, Geert Uytterhoeven wrote: >Hi Sasha, > >On Mon, Mar 19, 2018 at 5:12 PM, Sasha Levin ><[email protected]> wrote: >> From: Michael Schmitz <[email protected]> >> >> [ Upstream commit 9dfa7bba35ac08a63565d58c454dccb7e1bb0a08 ] >> >> get_reg() can be reentered on architectures with prioritized interrupts >> (m68k in this case), causing f->reg_index to be incremented after the >> range check. Out of bounds memory access past the pt_regs struct results. >> This will go mostly undetected unless access is beyond end of memory. >> >> Prevent the race by disabling interrupts in get_reg(). >> >> Tested on m68k (Atari Falcon, and ARAnyM emulator). >> >> Kudos to Geert Uytterhoeven for helping to trace this race. >> >> Signed-off-by: Michael Schmitz <[email protected]> >> Signed-off-by: Theodore Ts'o <[email protected]> >> Signed-off-by: Sasha Levin <[email protected]> > >You probably want to apply follow-up commit 92e75428ffc90e2a >("random: use lockless method of accessing and updating f->reg_idx"), too.
I've grabbed it too, thanks! -- Thanks, Sasha
