Infinite loop over ERANGE from getsockopt

[Fritz Katze]

Host system: Ubuntu 18.04.3 AMD64
Qemu Version: qemu-arm-static --version
qemu-arm version 2.11.1(Debian 1:2.11+dfsg-1ubuntu7.17)

Emulated System:
Root file system taken from RaspberryPi 3 image
ubuntu-18.04.3-preinstalled-server-armhf+raspi3.img
from http://cdimage.ubuntu.com/releases/18.04/release/ubuntu-18.04.3-preinstalled-server-armhf+raspi3.img.xz.

Then using system-nspawn with with /usr/bin/qemu-arm-static copied in.

When executing commands like
  dpkg -i (--force-all) <...>.deb
or
  tar tvf ..
or
  tar xvf ..
the hosting qemu-arm-static process goes into an infinite loop of getsockopt calls of the form:
getsockopt(12, SOL_SOCKET, SO_PEERSEC, 0x7fff7cac49d8, [4]) = -1 ERANGE (Numerical result out of range)
I assume that this is because of an infinite retry without checking the actual error code of the call.

strace:
openat(AT_FDCWD, "/lib/arm-linux-gnueabihf/librt.so.1", O_RDONLY|O_CLOEXEC) = 12
read(12, "\177ELF\1\1\1\3\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0\20\30\0\0004\0\0\0"..., 512) = 512
lseek(12, 21236, SEEK_SET) = 21236
read(12, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 1240) = 1240
lseek(12, 20856, SEEK_SET) = 20856
read(12, "A2\0\0\0aeabi\0\1(\0\0\0\0057-A\0\6\n\7A\10\1\t\2\n\4\22"..., 51) = 51
fstat(12, {st_mode=S_IFREG|0644, st_size=22476, ...}) = 0
mmap(0x7f419952c000, 90112, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS|MAP_DENYWRIT
E, -1, 0) = 0x7f419952c000
mmap(0x7f419952c000, 90112, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 12, 0) = 0x
7f419952c000
mprotect(0x7f4199531000, 61440, PROT_NONE) = 0
mmap(0x7f4199540000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 12, 0x4000)
 = 0x7f4199540000
close(12) = 0
mprotect(0x7f4199540000, 4096, PROT_READ) = 0
mprotect(0x7f4199578000, 8192, PROT_READ) = 0
mmap(0x7f419957b000, 28672, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0)
= 0x7f419957b000
rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
rt_sigprocmask(SIG_SETMASK, [HUP USR1 USR2 PIPE ALRM CHLD TSTP URG VTALRM PROF WINCH IO], NULL, 8
) = 0
access("/etc/systemd/dont-synthesize-nobody", F_OK) = -1 ENOENT (No such file or directory)
getpid() = 26
socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 12
getsockopt(12, SOL_SOCKET, SO_RCVBUF, [212992], [4]) = 0
setsockopt(12, SOL_SOCKET, SO_RCVBUFFORCE, [8388608], 4) = -1 EPERM (Operation not permitted)
setsockopt(12, SOL_SOCKET, SO_RCVBUF, [8388608], 4) = 0
getsockopt(12, SOL_SOCKET, SO_SNDBUF, [212992], [4]) = 0
setsockopt(12, SOL_SOCKET, SO_SNDBUFFORCE, [8388608], 4) = -1 EPERM (Operation not permitted)
setsockopt(12, SOL_SOCKET, SO_SNDBUF, [8388608], 4) = 0
connect(12, {sa_family=AF_UNIX, sun_path="/run/dbus/system_bus_socket"}, 29) = 0
getsockopt(12, SOL_SOCKET, SO_PEERCRED, {pid=0, uid=0, gid=0}, [12]) = 0
getsockopt(12, SOL_SOCKET, SO_PEERSEC, 0x7fff7cac49d8, [4]) = -1 ERANGE (Numerical result out of
range)

And this last entry repeats endlessly.

[Peter Maydell (pmaydell)]

Hi; thanks for this bug report. It looks like it's the same as LP:1823790. The underlying cause is that we don't implement the SO_PEERSEC getsockopt option properly. Unfortunately this option appears to be completely undocumented, which makes it pretty hard for us to implement :-(

[Fritz Katze (fritz-the-cat)]

See my comment at LP:1823790.