From ce29856a5e1aabe52e18b2c60db1490769a6ab55 Mon Sep 17 00:00:00 2001 From: Mickaël Salaün <mic@digikod.net> Date: Mon, 1 Aug 2016 23:01:56 +0200 Subject: um/ptrace: Fix the syscall number update after a ptrace MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Update the syscall number after each PTRACE_SETREGS on ORIG_*AX. This is needed to get the potentially altered syscall number in the seccomp filters after RET_TRACE. This fix four seccomp_bpf tests: > [ RUN ] TRACE_syscall.skip_after_RET_TRACE > seccomp_bpf.c:1560:TRACE_syscall.skip_after_RET_TRACE:Expected -1 (18446744073709551615) == syscall(39) (26) > seccomp_bpf.c:1561:TRACE_syscall.skip_after_RET_TRACE:Expected 1 (1) == (*__errno_location ()) (22) > [ FAIL ] TRACE_syscall.skip_after_RET_TRACE > [ RUN ] TRACE_syscall.kill_after_RET_TRACE > TRACE_syscall.kill_after_RET_TRACE: Test exited normally instead of by signal (code: 1) > [ FAIL ] TRACE_syscall.kill_after_RET_TRACE > [ RUN ] TRACE_syscall.skip_after_ptrace > seccomp_bpf.c:1622:TRACE_syscall.skip_after_ptrace:Expected -1 (18446744073709551615) == syscall(39) (26) > seccomp_bpf.c:1623:TRACE_syscall.skip_after_ptrace:Expected 1 (1) == (*__errno_location ()) (22) > [ FAIL ] TRACE_syscall.skip_after_ptrace > [ RUN ] TRACE_syscall.kill_after_ptrace > TRACE_syscall.kill_after_ptrace: Test exited normally instead of by signal (code: 1) > [ FAIL ] TRACE_syscall.kill_after_ptrace Fixes: 26703c636c1f ("um/ptrace: run seccomp after ptrace") Signed-off-by: Mickaël Salaün <mic@digikod.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: James Morris <jmorris@namei.org> Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Kees Cook <keescook@chromium.org> --- arch/um/kernel/skas/syscall.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'arch/um') diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c index 0728fee94398..b783ac87d98a 100644 --- a/arch/um/kernel/skas/syscall.c +++ b/arch/um/kernel/skas/syscall.c @@ -27,12 +27,7 @@ void handle_syscall(struct uml_pt_regs *r) if (secure_computing(NULL) == -1) goto out; - /* Update the syscall number after orig_ax has potentially been updated - * with ptrace. - */ - UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp); syscall = UPT_SYSCALL_NR(r); - if (syscall >= 0 && syscall <= __NR_syscall_max) PT_REGS_SET_SYSCALL_RETURN(regs, EXECUTE_SYSCALL(syscall, regs)); -- cgit v1.2.3-58-ga151