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| author | kib <kib@FreeBSD.org> | 2014-07-09 21:39:40 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2014-07-09 21:39:40 +0000 |
| commit | 729061be23933eef604d4544c9dcbfbdbfae737e (patch) | |
| tree | 6b2134ae407819edaf1c50b982dde95b46f6672b /sys/amd64 | |
| parent | 9b45140041c09da644d27b76a72bd4d08340b70c (diff) | |
| download | FreeBSD-src-729061be23933eef604d4544c9dcbfbdbfae737e.zip FreeBSD-src-729061be23933eef604d4544c9dcbfbdbfae737e.tar.gz | |
For safety, ensure that any consumer of the set_regs() and
ptrace_set_pc() use the correct return to userspace using iret.
The signal return, PT_CONTINUE (which in fact uses signal return path)
set the pcb flag already. The setcontext(2) enforces iret return when
%rip is incorrect. Due to this, the change is redundand, but is made
to ensure that no path which modifies context, forgets to set
PCB_FULL_IRET.
Inspired by: CVE-2014-4699
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Diffstat (limited to 'sys/amd64')
| -rw-r--r-- | sys/amd64/amd64/machdep.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c index 82c2c89..5afd58c 100644 --- a/sys/amd64/amd64/machdep.c +++ b/sys/amd64/amd64/machdep.c @@ -2144,7 +2144,9 @@ makectx(struct trapframe *tf, struct pcb *pcb) int ptrace_set_pc(struct thread *td, unsigned long addr) { + td->td_frame->tf_rip = addr; + set_pcb_flags(td->td_pcb, PCB_FULL_IRET); return (0); } @@ -2244,8 +2246,8 @@ set_regs(struct thread *td, struct reg *regs) tp->tf_fs = regs->r_fs; tp->tf_gs = regs->r_gs; tp->tf_flags = TF_HASSEGS; - set_pcb_flags(td->td_pcb, PCB_FULL_IRET); } + set_pcb_flags(td->td_pcb, PCB_FULL_IRET); return (0); } |
