[Qemu-devel] [PATCH v2] seccomp: add timerfd_create and timerfd_settime to the whitelist

[Qemu-devel] [PATCH v2] seccomp: add timerfd_create and timerfd_settime to the whitelist

[Felix Geyer]

libusb calls timerfd_create() and timerfd_settime() when it's built with
timerfd support.

Command to reproduce:

       -device usb-host,hostbus=1,hostaddr=3,id=hostdev0

Log messages:

audit(1390730418.924:135): auid=4294967295 uid=121 gid=103 ses=4294967295
                           pid=5232 comm="qemu-system-x86" sig=31 syscall=283
                           compat=0 ip=0x7f2b0f4e96a7 code=0x0
audit(1390733100.580:142): auid=4294967295 uid=121 gid=103 ses=4294967295
                           pid=16909 comm="qemu-system-x86" sig=31 syscall=286
                           compat=0 ip=0x7f03513a06da code=0x0

Reading a few hundred MB from a USB drive on x86_64 shows this syscall distribution.
Therefore the timerfd_settime priority is set to 242.

    calls  syscall
 --------- ----------------
   5303600 write
   2240554 read
   2167030 ppoll
   2134828 ioctl
    704023 timerfd_settime
    689105 poll
     83122 futex
       803 writev
       476 rt_sigprocmask
       287 recvmsg
       178 brk

Signed-off-by: Felix Geyer <debfx@fobos.de>
---
 qemu-seccomp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/qemu-seccomp.c b/qemu-seccomp.c
index caa926e..b00922c 100644
--- a/qemu-seccomp.c
+++ b/qemu-seccomp.c
@@ -143,6 +143,7 @@ static const struct QemuSeccompSyscall seccomp_whitelist[] = {
     { SCMP_SYS(getsockname), 242 },
     { SCMP_SYS(getpeername), 242 },
     { SCMP_SYS(accept4), 242 },
+    { SCMP_SYS(timerfd_settime), 242 },
     { SCMP_SYS(newfstatat), 241 },
     { SCMP_SYS(shutdown), 241 },
     { SCMP_SYS(getsockopt), 241 },
@@ -225,7 +226,8 @@ static const struct QemuSeccompSyscall seccomp_whitelist[] = {
     { SCMP_SYS(fchmod), 240 },
     { SCMP_SYS(shmget), 240 },
     { SCMP_SYS(shmat), 240 },
-    { SCMP_SYS(shmdt), 240 }
+    { SCMP_SYS(shmdt), 240 },
+    { SCMP_SYS(timerfd_create), 240 }
 };

 int seccomp_start(void)
-- 
1.9.rc1

Re: [Qemu-devel] [PATCH v2] seccomp: add timerfd_create and timerfd_settime to the whitelist

[Eduardo Otubo]

On 01/30/2014 06:28 PM, Felix Geyer wrote:
> libusb calls timerfd_create() and timerfd_settime() when it's built with
> timerfd support.
>
> Command to reproduce:
>
>         -device usb-host,hostbus=1,hostaddr=3,id=hostdev0
>
> Log messages:
>
> audit(1390730418.924:135): auid=4294967295 uid=121 gid=103 ses=4294967295
>                             pid=5232 comm="qemu-system-x86" sig=31 syscall=283
>                             compat=0 ip=0x7f2b0f4e96a7 code=0x0
> audit(1390733100.580:142): auid=4294967295 uid=121 gid=103 ses=4294967295
>                             pid=16909 comm="qemu-system-x86" sig=31 syscall=286
>                             compat=0 ip=0x7f03513a06da code=0x0
>
> Reading a few hundred MB from a USB drive on x86_64 shows this syscall distribution.
> Therefore the timerfd_settime priority is set to 242.
>
>      calls  syscall
>   --------- ----------------
>     5303600 write
>     2240554 read
>     2167030 ppoll
>     2134828 ioctl
>      704023 timerfd_settime
>      689105 poll
>       83122 futex
>         803 writev
>         476 rt_sigprocmask
>         287 recvmsg
>         178 brk
>
> Signed-off-by: Felix Geyer <debfx@fobos.de>
> ---
>   qemu-seccomp.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/qemu-seccomp.c b/qemu-seccomp.c
> index caa926e..b00922c 100644
> --- a/qemu-seccomp.c
> +++ b/qemu-seccomp.c
> @@ -143,6 +143,7 @@ static const struct QemuSeccompSyscall seccomp_whitelist[] = {
>       { SCMP_SYS(getsockname), 242 },
>       { SCMP_SYS(getpeername), 242 },
>       { SCMP_SYS(accept4), 242 },
> +    { SCMP_SYS(timerfd_settime), 242 },
>       { SCMP_SYS(newfstatat), 241 },
>       { SCMP_SYS(shutdown), 241 },
>       { SCMP_SYS(getsockopt), 241 },
> @@ -225,7 +226,8 @@ static const struct QemuSeccompSyscall seccomp_whitelist[] = {
>       { SCMP_SYS(fchmod), 240 },
>       { SCMP_SYS(shmget), 240 },
>       { SCMP_SYS(shmat), 240 },
> -    { SCMP_SYS(shmdt), 240 }
> +    { SCMP_SYS(shmdt), 240 },
> +    { SCMP_SYS(timerfd_create), 240 }
>   };
>
>   int seccomp_start(void)
>

ACK

-- 
Eduardo Otubo
IBM Linux Technology Center