From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49035) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dqFJO-0001CC-U3 for qemu-devel@nongnu.org; Fri, 08 Sep 2017 05:11:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dqFJK-0002uD-10 for qemu-devel@nongnu.org; Fri, 08 Sep 2017 05:10:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38874) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dqFJJ-0002tC-K2 for qemu-devel@nongnu.org; Fri, 08 Sep 2017 05:10:49 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BC5FCC047B62 for ; Fri, 8 Sep 2017 09:10:48 +0000 (UTC) From: Eduardo Otubo Date: Fri, 8 Sep 2017 11:10:24 +0200 Message-Id: <20170908091027.9104-3-otubo@redhat.com> In-Reply-To: <20170908091027.9104-1-otubo@redhat.com> References: <20170908091027.9104-1-otubo@redhat.com> Subject: [Qemu-devel] [PATCHv5 2/5] seccomp: add obsolete argument to command line List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: thuth@redhat.com, "Daniel P . Berrange" This patch introduces the argument [,obsolete=allow] to the `-sandbox on' option. It allows Qemu to run safely on old system that still relies on old system calls. Signed-off-by: Eduardo Otubo --- include/sysemu/seccomp.h | 3 ++- qemu-options.hx | 12 ++++++++++-- qemu-seccomp.c | 20 +++++++++++++++++++- vl.c | 22 +++++++++++++++++++++- 4 files changed, 52 insertions(+), 5 deletions(-) diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index 23b9c3c789..215138a372 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -16,8 +16,9 @@ #define QEMU_SECCOMP_H #define QEMU_SECCOMP_SET_DEFAULT (1 << 0) +#define QEMU_SECCOMP_SET_OBSOLETE (1 << 1) #include -int seccomp_start(void); +int seccomp_start(uint32_t seccomp_opts); #endif diff --git a/qemu-options.hx b/qemu-options.hx index 9f6e2adfff..72150c6b84 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4017,13 +4017,21 @@ Old param mode (ARM only). ETEXI DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ - "-sandbox Enable seccomp mode 2 system call filter (default 'off').\n", + "-sandbox on[,obsolete=allow|deny]\n" \ + " Enable seccomp mode 2 system call filter (default 'off').\n" \ + " use 'obsolete' to allow obsolete system calls that are provided\n" \ + " by the kernel, but typically no longer used by modern\n" \ + " C library implementations.\n", QEMU_ARCH_ALL) STEXI -@item -sandbox @var{arg} +@item -sandbox @var{arg}[,obsolete=@var{string}] @findex -sandbox Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will disable it. The default is 'off'. +@table @option +@item obsolete=@var{string} +Enable Obsolete system calls +@end table ETEXI DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, diff --git a/qemu-seccomp.c b/qemu-seccomp.c index bc9a1f77ff..126e5ee2d5 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -56,9 +56,22 @@ static const struct QemuSeccompSyscall blacklist[] = { { SCMP_SYS(tuxcall), 1, QEMU_SECCOMP_SET_DEFAULT }, { SCMP_SYS(ulimit), 1, QEMU_SECCOMP_SET_DEFAULT }, { SCMP_SYS(vserver), 1, QEMU_SECCOMP_SET_DEFAULT }, + /* obsolete */ + { SCMP_SYS(readdir), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(_sysctl), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(bdflush), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(create_module), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(get_kernel_syms), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(query_module), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(sgetmask), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(ssetmask), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(sysfs), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(uselib), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(ustat), 2, QEMU_SECCOMP_SET_OBSOLETE }, }; -int seccomp_start(void) + +int seccomp_start(uint32_t seccomp_opts) { int rc = 0; unsigned int i = 0; @@ -72,6 +85,11 @@ int seccomp_start(void) for (i = 0; i < ARRAY_SIZE(blacklist); i++) { switch (blacklist[i].set) { + case QEMU_SECCOMP_SET_OBSOLETE: + if ((seccomp_opts & QEMU_SECCOMP_SET_OBSOLETE)) { + continue; + } + break; default: break; } diff --git a/vl.c b/vl.c index 76e0b3a946..dafbe30e2b 100644 --- a/vl.c +++ b/vl.c @@ -271,6 +271,10 @@ static QemuOptsList qemu_sandbox_opts = { .name = "enable", .type = QEMU_OPT_BOOL, }, + { + .name = "obsolete", + .type = QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -1034,7 +1038,23 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp) { if (qemu_opt_get_bool(opts, "enable", false)) { #ifdef CONFIG_SECCOMP - if (seccomp_start() < 0) { + uint32_t seccomp_opts = 0x00000; + const char *value = NULL; + + value = qemu_opt_get(opts, "obsolete"); + if (value) { + if (g_str_equal(value, "allow")) { + seccomp_opts |= QEMU_SECCOMP_SET_OBSOLETE; + } else if (g_str_equal(value, "deny")) { + /* this is the default option, this if is here + * to provide a little bit of consistency for + * the command line */ + } else { + error_report("invalid argument for obsolete"); + } + } + + if (seccomp_start(seccomp_opts) < 0) { error_report("failed to install seccomp syscall filter " "in the kernel"); return -1; -- 2.13.5