Re: [Libguestfs] Issue with downloading files whose path contains multi-byte utf-8 characters

The attached code snippet reproduces the issue when running: python3 libugestfs_segfault_repro.py With: guestfs version: 1.48.6 guestfs-python version: 1.48.6

Stacktrace: #0  0x00007f6dd17b4701 in _Py_INCREF (op=<optimized out>) at /usr/include/ python3.9/object.h:408 408    op->ob_refcnt++; (gdb) bt #0  0x00007f6dd17b4701 in _Py_INCREF (op=<optimized out>) at /usr/include/ python3.9/object.h:408 #1  guestfs_int_py_event_callback_wrapper     (g=<optimized out>, flags=<optimized out>, array_len=0, array=0x0, buf_len= 43, buf=0xd1dc90 "commandrvf: udevadm --debug settle -E /\347\232\204\303 available\r\ned7 #2  guestfs_int_py_event_callback_wrapper     (g=<optimized out>, callback=0x7f6dd19ec040, event=16, event_handle=0, flags=<optimized out>, buf=0xd1dc90 "commandrvf: udevadm --debug settle -E /\ 347\232\204\303 4 #3  0x00007f6dd166f9aa in guestfs_int_call_callbacks_message     (g=0xae06f0, event=16, buf=0xd1dc90 "commandrvf: udevadm --debug settle -E /\347\232\204\303 available\r\ned to rvf:e run  in, ignor data av", buf_len=43)     at events.c:117 #4  0x00007f6dd168560e in guestfs_int_log_message_callback     (g=g@entry=0xae06f0, buf=0xd1dc90 "commandrvf: udevadm --debug settle -E /\ 347\232\204\303 available\r\ned to rvf:e run  in, ignor data av", len=len@entry =43)     at proto.c:145 #5  0x00007f6dd166ac29 in handle_log_message (g=g@entry=0xae06f0, conn= conn@entry=0xd19570) at conn-socket.c:395 #6  0x00007f6dd166b233 in read_data (len=4, bufv=<optimized out>, connv= <optimized out>, g=<optimized out>) at conn-socket.c:179 #7  read_data (g=0xae06f0, connv=0xd19570, bufv=<optimized out>, len=4) at conn-socket.c:142 #8  0x00007f6dd1685c2a in recv_from_daemon (buf_rtn=0x7fffa95cc548, size_rtn= 0x7fffa95cc544, g=0xae06f0) at proto.c:545 #9  guestfs_int_recv_from_daemon (g=g@entry=0xae06f0, size_rtn=size_rtn@entry= 0x7fffa95cc544, buf_rtn=buf_rtn@entry=0x7fffa95cc548) at proto.c:623 #10 0x00007f6dd168603a in guestfs_int_recv     (g=g@entry=0xae06f0, fn=fn@entry=0x7f6dd16aa308 "download", hdr=hdr@entry= 0x7fffa95cc610, err=err@entry=0x7fffa95cc5e0, xdrp=xdrp@entry=0x0, ret= ret@entry=0x0)     at proto.c:668 #11 0x00007f6dd163825e in guestfs_download (g=g@entry=0xae06f0, remotefilename= <optimized out>, filename=0x7f6dd17edea0 "/tmp/1") at actions-5.c:2984 #12 0x00007f6dd17ab01a in guestfs_int_py_download (self=<optimized out>, args= <optimized out>) at actions-5.c:794   On Mon, Feb 13, 2023 at 10:16 PM Richard W.M. Jones <rjones(a)redhat.com&gt; wrote: On Mon, Feb 13, 2023 at 09:38:50PM +0200, Yonatan Shtarkman wrote: > Also, as a workaround, I avoided calling the event callback if null is returned > by Py_BuildValue (still print the error and release the thread). > This seems to work for our usage (we only use the event callbacks for logging), > any potential issues I'm missing? Oh I see so the issue is actually when logging and not in the download call?  That's strange that it should be happening intermittently.  I'd expect a UTF-8 encoding error would happen every time not sometimes. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/ ~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines.  Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top

import guestfs from guestfs import GuestFS g = GuestFS(python_return_dict=True) def callback(event, _event_handle, buf: str, array): pass g.set_event_callback(callback, guestfs.EVENT_ALL) g.set_verbose(True) path = '/tmp/tmp_disk' g.disk_create(path, format='raw', size=32*1024*1024) g.add_drive(path) g.launch() g.mkfs('ext4', '/dev/sda') g.mount('/dev/sda', '/') for _ in range(20000): try: g.download ('/的ó', '/tmp/1') except: pass