On Thu, Mar 23, 2017 at 3:46 PM, Kees Cook <[email protected]> wrote: > Commit aa1f1a639621 ("lib/syscall: Pin the task stack in collect_syscall()") > added logic to handle a process stack not existing, but left sp and pc > uninitialized, which can be later reported via /proc/$pid/syscall for zombie > processes, potentially exposing kernel memory to userspace. > > Zombie /proc/$pid/syscall before: > -1 0xffffffff9a060100 0xffff92f42d6ad900 > > Zombie /proc/$pid/syscall after: > -1 0x0 0x0 > > Reported-by: Robert Święcki <[email protected]> > Fixes: aa1f1a639621 ("lib/syscall: Pin the task stack in collect_syscall()") > Cc: [email protected] # v4.9+ > Signed-off-by: Kees Cook <[email protected]>
Whoops! Reviewed-by: Andy Lutomirski <[email protected]>
