From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54776) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TPIrz-0002lm-MI for qemu-devel@nongnu.org; Fri, 19 Oct 2012 16:08:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TPIry-0000Uj-4n for qemu-devel@nongnu.org; Fri, 19 Oct 2012 16:08:35 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:46702) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TPIry-0000UF-0R for qemu-devel@nongnu.org; Fri, 19 Oct 2012 16:08:34 -0400 Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 19 Oct 2012 16:08:32 -0400 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id DDEB8C90049 for ; Fri, 19 Oct 2012 16:08:29 -0400 (EDT) Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q9JK8TCC306944 for ; Fri, 19 Oct 2012 16:08:29 -0400 Received: from d03av05.boulder.ibm.com (loopback [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q9JK8JW2026218 for ; Fri, 19 Oct 2012 14:08:20 -0600 Message-ID: <5081B330.3060106@linux.vnet.ibm.com> Date: Fri, 19 Oct 2012 16:08:16 -0400 From: Corey Bryant MIME-Version: 1.0 References: <1350479712-15082-1-git-send-email-otubo@linux.vnet.ibm.com> <1350479712-15082-3-git-send-email-otubo@linux.vnet.ibm.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 3/4] Support for "double whitelist" filters List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl , Eduardo Otubo Cc: pmoore@redhat.com, aliguori@us.ibm.com, qemu-devel@nongnu.org On 10/19/2012 01:04 PM, Blue Swirl wrote: > On Wed, Oct 17, 2012 at 1:15 PM, Eduardo Otubo wrote: >> This patch includes a second whitelist right before the main loop. It's >> a smaller and more restricted whitelist, excluding execve() among many >> others. >> >> Signed-off-by: Eduardo Otubo >> --- >> qemu-seccomp.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++------ >> qemu-seccomp.h | 7 ++++- >> vl.c | 13 +++++++- >> 3 files changed, 103 insertions(+), 11 deletions(-) >> >> diff --git a/qemu-seccomp.c b/qemu-seccomp.c >> index a25f2fa..9c68af5 100644 >> --- a/qemu-seccomp.c >> +++ b/qemu-seccomp.c >> @@ -13,6 +13,7 @@ >> * GNU GPL, version 2 or (at your option) any later version. >> */ >> #include >> +#include >> #include >> #include "qemu-seccomp.h" >> >> @@ -21,7 +22,7 @@ struct QemuSeccompSyscall { >> uint8_t priority; >> }; >> >> -static const struct QemuSeccompSyscall seccomp_whitelist[] = { >> +static const struct QemuSeccompSyscall seccomp_whitelist_init[] = { >> { SCMP_SYS(timer_settime), 255 }, >> { SCMP_SYS(timer_gettime), 254 }, >> { SCMP_SYS(futex), 253 }, >> @@ -118,27 +119,102 @@ static const struct QemuSeccompSyscall seccomp_whitelist[] = { >> { SCMP_SYS(accept4), 242 } >> }; >> >> -int seccomp_start(void) >> +static const struct QemuSeccompSyscall seccomp_whitelist_main_loop[] = { >> + { SCMP_SYS(timer_settime), 255 }, >> + { SCMP_SYS(timer_gettime), 254 }, >> + { SCMP_SYS(futex), 253 }, >> + { SCMP_SYS(select), 252 }, >> + { SCMP_SYS(recvfrom), 251 }, >> + { SCMP_SYS(sendto), 250 }, >> + { SCMP_SYS(read), 249 }, >> + { SCMP_SYS(brk), 248 }, >> + { SCMP_SYS(mmap), 247 }, >> +#if defined(__i386__) >> + { SCMP_SYS(fcntl64), 245 }, >> + { SCMP_SYS(fstat64), 245 }, >> + { SCMP_SYS(stat64), 245 }, >> + { SCMP_SYS(getgid32), 245 }, >> + { SCMP_SYS(getegid32), 245 }, >> + { SCMP_SYS(getuid32), 245 }, >> + { SCMP_SYS(geteuid32), 245 }, >> + { SCMP_SYS(sigreturn), 245 }, >> + { SCMP_SYS(_newselect), 245 }, >> + { SCMP_SYS(_llseek), 245 }, >> + { SCMP_SYS(mmap2), 245}, >> + { SCMP_SYS(sigprocmask), 245 }, >> +#endif >> + { SCMP_SYS(exit), 245 }, >> + { SCMP_SYS(timer_delete), 245 }, >> + { SCMP_SYS(exit_group), 245 }, >> + { SCMP_SYS(rt_sigreturn), 245 }, >> + { SCMP_SYS(madvise), 245 }, >> + { SCMP_SYS(write), 244 }, >> + { SCMP_SYS(fcntl), 243 }, >> + { SCMP_SYS(tgkill), 242 }, >> + { SCMP_SYS(rt_sigaction), 242 }, >> + { SCMP_SYS(pipe2), 242 }, >> + { SCMP_SYS(munmap), 242 }, >> + { SCMP_SYS(mremap), 242 }, >> + { SCMP_SYS(getsockname), 242 }, >> + { SCMP_SYS(getpeername), 242 }, >> + { SCMP_SYS(close), 242 }, >> + { SCMP_SYS(accept4), 242 } > > It's nice to see that for example open, creat, unlink, socket, bind, > mprotect, setrlimit and kill are not present. > Hmm, well open minimally needs to be added to this list so that drives can be hotplugged. >> +}; >> + >> +static int >> +process_whitelist(const struct QemuSeccompSyscall *whitelist, >> + unsigned int size, scmp_filter_ctx *ctx) >> { >> int rc = 0; >> + >> unsigned int i = 0; >> - scmp_filter_ctx ctx; >> + >> + for (i = 0; i < size; i++) { >> + rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, whitelist[i].num, 0); >> + if (rc < 0) { >> + return -1; >> + } >> + >> + rc = seccomp_syscall_priority(ctx, whitelist[i].num, >> + whitelist[i].priority); >> + if (rc < 0) { >> + return -1; >> + } >> + } >> + return 0; >> +} >> + >> +int >> +seccomp_start(enum whitelist_mode mode, scmp_filter_ctx *ctx) >> +{ >> + int rc = 0; >> >> ctx = seccomp_init(SCMP_ACT_KILL); >> if (ctx == NULL) { >> + rc = -1; >> goto seccomp_return; >> } >> >> - for (i = 0; i < ARRAY_SIZE(seccomp_whitelist); i++) { >> - rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, seccomp_whitelist[i].num, 0); >> - if (rc < 0) { >> + switch (mode) { >> + case INIT: >> + if (process_whitelist >> + (seccomp_whitelist_init, >> + ARRAY_SIZE(seccomp_whitelist_init), ctx) < 0) { >> + rc = -1; >> goto seccomp_return; >> } >> - rc = seccomp_syscall_priority(ctx, seccomp_whitelist[i].num, >> - seccomp_whitelist[i].priority); >> - if (rc < 0) { >> + break; >> + case MAIN_LOOP: >> + if (process_whitelist >> + (seccomp_whitelist_main_loop, >> + ARRAY_SIZE(seccomp_whitelist_main_loop), ctx) < 0) { >> + rc = -1; >> goto seccomp_return; >> } >> + break; >> + default: >> + rc = -1; >> + goto seccomp_return; >> } >> >> rc = seccomp_load(ctx); >> diff --git a/qemu-seccomp.h b/qemu-seccomp.h >> index b2fc3f8..1c97978 100644 >> --- a/qemu-seccomp.h >> +++ b/qemu-seccomp.h >> @@ -18,5 +18,10 @@ >> #include >> #include "osdep.h" >> >> -int seccomp_start(void); >> +enum whitelist_mode { >> + INIT = 0, >> + MAIN_LOOP = 1, >> +}; >> + >> +int seccomp_start(enum whitelist_mode mode, scmp_filter_ctx *ctx); >> #endif >> diff --git a/vl.c b/vl.c >> index bec68cd..773d488 100644 >> --- a/vl.c >> +++ b/vl.c >> @@ -278,6 +278,7 @@ static int default_vga = 1; >> >> #ifdef CONFIG_SECCOMP >> bool seccomp_on = true; >> +scmp_filter_ctx ctx; > > This should be a local variable to main(), maybe also named > 'main_loop_ctx' so we can add further contexts. > >> #endif >> >> static struct { >> @@ -777,7 +778,7 @@ static int bt_parse(const char *opt) >> static int install_seccomp_filters(void) >> { >> #ifdef CONFIG_SECCOMP >> - if (seccomp_start() < 0) { >> + if (seccomp_start(INIT, &ctx) < 0) { >> qerror_report(ERROR_CLASS_GENERIC_ERROR, >> "failed to install seccomp syscall filter in the kernel"); >> return -1; >> @@ -3794,6 +3795,16 @@ int main(int argc, char **argv, char **envp) >> >> os_setup_post(); >> >> + if (seccomp_on) { > > 'seccomp_on' is only available with CONFIG_SECCOMP, so this would break build. > >> +#ifdef CONFIG_SECCOMP >> + if (seccomp_start(MAIN_LOOP, &ctx) < 0) { >> + qerror_report(ERROR_CLASS_GENERIC_ERROR, >> + "failed to install seccomp syscall filter in the kernel"); > > This error message could be different from the first one. > >> + return -1; >> + } >> +#endif >> + } >> + >> resume_all_vcpus(); >> main_loop(); >> bdrv_close_all(); >> -- >> 1.7.12 >> >> > > -- Regards, Corey Bryant