Author: jhb Date: Wed Aug 12 20:33:29 2020 New Revision: 364181 URL: https://svnweb.freebsd.org/changeset/base/364181
Log: Check that the frame pointer is within the current stack. This same check is used on other architectures. Previously this would permit a stack frame to unwind into any arbitrary kernel address (including unmapped addresses). Reviewed by: mhorne Obtained from: CheriBSD Sponsored by: DARPA Differential Revision: https://reviews.freebsd.org/D25996 Modified: head/sys/riscv/riscv/stack_machdep.c Modified: head/sys/riscv/riscv/stack_machdep.c ============================================================================== --- head/sys/riscv/riscv/stack_machdep.c Wed Aug 12 20:29:49 2020 (r364180) +++ head/sys/riscv/riscv/stack_machdep.c Wed Aug 12 20:33:29 2020 (r364181) @@ -47,15 +47,18 @@ __FBSDID("$FreeBSD$"); #include <machine/stack.h> static void -stack_capture(struct stack *st, struct unwind_state *frame) +stack_capture(struct thread *td, struct stack *st, struct unwind_state *frame) { stack_zero(st); while (1) { + if ((vm_offset_t)frame->fp < td->td_kstack || + (vm_offset_t)frame->fp >= td->td_kstack + + td->td_kstack_pages * PAGE_SIZE) + break; unwind_frame(frame); - if (!INKERNEL((vm_offset_t)frame->fp) || - !INKERNEL((vm_offset_t)frame->pc)) + if (!INKERNEL((vm_offset_t)frame->pc)) break; if (stack_put(st, frame->pc) == -1) break; @@ -78,7 +81,7 @@ stack_save_td(struct stack *st, struct thread *td) frame.fp = td->td_pcb->pcb_s[0]; frame.pc = td->td_pcb->pcb_ra; - stack_capture(st, &frame); + stack_capture(td, st, &frame); return (0); } @@ -94,5 +97,5 @@ stack_save(struct stack *st) frame.fp = (uintptr_t)__builtin_frame_address(0); frame.pc = (uintptr_t)stack_save; - stack_capture(st, &frame); + stack_capture(curthread, st, &frame); } _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
