Module Name: src
Committed By: maxv
Date: Sun Feb 25 13:09:34 UTC 2018
Modified Files:
src/sys/arch/amd64/amd64: trap.c
Log Message:
Mmh. We shouldn't read %cr2 here. %cr2 is initialized by the CPU only
during page faults (T_PAGEFLT), so here we're reading a value that comes
from a previous page fault.
That's a real problem; if you launch an unprivileged process, set up a
signal handler, make it sleep 10 seconds, and trigger a T_ALIGNFLT fault,
you get in si_addr the address of another LWP's page - and perhaps this
can be used to defeat userland ASLR.
This bug has been there since 2003.
To generate a diff of this commit:
cvs rdiff -u -r1.112 -r1.113 src/sys/arch/amd64/amd64/trap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
