Looks like culprit is libnss_resonve.so. First of all, to reproduce, I have to use hostname like google.com. If I give traceroute an IP address, there are no setsockopt calls that needs net_admin cap.
Here's gdb log, breakpointed on setsockopt, dumped registers (you can see rdx set to "33" so that's one of SO_RCVBUFFORCE/SO_SNDBUFFORCE), and backtrace, that leads to /lib/x86_64-linux-gnu/libnss_resolve.so.2: Breakpoint 1 (setsockopt) pending. Starting program: /usr/sbin/traceroute -T google.com [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Breakpoint 1, setsockopt () at ../sysdeps/unix/syscall-template.S:84 84 ../sysdeps/unix/syscall-template.S: No such file or directory. rax 0x34000 212992 rbx 0x55ad9953abe0 94204090100704 rcx 0x7ffc27aac6d0 140720973989584 rdx 0x21 33 rsi 0x1 1 rdi 0x3 3 rbp 0x7ffc27aac6d0 0x7ffc27aac6d0 rsp 0x7ffc27aac6c8 0x7ffc27aac6c8 r8 0x4 4 r9 0x0 0 r10 0x7ffc27aac6d0 140720973989584 r11 0x202 514 r12 0x3 3 r13 0x7ffc27aac6d4 140720973989588 r14 0x7ffc27aac760 140720973989728 r15 0x55ad9953abe0 94204090100704 rip 0x7f057a78a320 0x7f057a78a320 <setsockopt> eflags 0x293 [ CF AF SF IF ] cs 0x33 51 ss 0x2b 43 ds 0x0 0 es 0x0 0 fs 0x0 0 gs 0x0 0 #0 setsockopt () at ../sysdeps/unix/syscall-template.S:84 #1 0x00007f057af2cd43 in ?? () from /lib/x86_64-linux-gnu/libnss_resolve.so.2 #2 0x00007f057af1ccd5 in ?? () from /lib/x86_64-linux-gnu/libnss_resolve.so.2 #3 0x00007f057af46f02 in ?? () from /lib/x86_64-linux-gnu/libnss_resolve.so.2 #4 0x00007f057af2287d in _nss_resolve_gethostbyname4_r () from /lib/x86_64-linux-gnu/libnss_resolve.so.2 #5 0x00007f057a76e16f in gaih_inet (name=name@entry=0x7ffc27aae76e "google.com", service=<optimized out>, req=req@entry=0x7ffc27aad400, pai=pai@entry=0x7ffc27aacf28, naddrs=naddrs@entry=0x7ffc27aacf24, tmpbuf=tmpbuf@entry=0x7ffc27aacf90) at ../sysdeps/posix/getaddrinfo.c:848 #6 0x00007f057a770448 in __GI_getaddrinfo (name=<optimized out>, service=<optimized out>, hints=0x7ffc27aad400, pai=0x7ffc27aad3f8) at ../sysdeps/posix/getaddrinfo.c:2391 #7 0x000055ad9791e326 in ?? () #8 0x000055ad9791e4b3 in ?? () #9 0x000055ad97921cae in ?? () #10 0x000055ad9791a7d1 in ?? () #11 0x00007f057a6a13f1 in __libc_start_main (main=0x55ad9791a700, argc=3, argv=0x7ffc27aad888, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffc27aad878) at ../csu/libc-start.c:291 #12 0x000055ad9791b3fa in ?? () ** Also affects: systemd (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1703649 Title: Traceroute needs net_admin capability for unknown reason To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1703649/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs