October 2026 - Libguestfs - libguestfs List Archives

Updated signing key for libguestfs-related packages
by Richard W.M. Jones 30 Oct '26

30 Oct '26

I've started to sign new release tarballs with an updated public key that uses only SHA512 hashes: https://download.libguestfs.org/rich@annexia.org-pubkey.txt The previous one that was used to sign packages had SHA1 hashes and was therefore judged to be insecure. It is still available here [actually as a GPG binary key ring, for reasons]: https://download.libguestfs.org/libguestfs.keyring Hopefully this all works, but as always with GPG stuff it's very obscure and could have gone wrong. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html

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Feature Request: Publish pre-built fixed appliance binaries for ppc64le (and offer for support)
by Punith Kenchappa 22 Oct '26

22 Oct '26

Hi Richard and the libguestfs team, We are currently using libguestfs as part of our automated build pipeline (via Bazel) and rely on pulling the pre-built fixed appliance tarballs from [http://libguestfs.org/download/binaries/appliance/](http://libguestfs.org/d…. We are expanding our support to the ppc64le architecture, but noticed that there are no official pre-built ppc64le appliance tarballs published in the upstream binaries directory. Could we request that ppc64le tarballs be published alongside the existing amd64/x86_64 appliances for future releases? We understand that publishing multi-architecture binaries often comes down to CI/CD limitations or a lack of dedicated hardware. If there are any limitations preventing the project from building and hosting ppc64le appliances, please let us know. We would be happy to offer our support—whether that involves contributing build scripts, testing the ppc64leartifacts, or helping provide/sponsor the necessary ppc64le build runner infrastructure to make this possible. Thank you for your time and for maintaining such a critical tool. Best regards, Punith Kenchappa Email: pkenchap(a)redhat.com Partner engineer (IBM)

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nbdkit golang bindings: Debug() and Error() leak the C.CString they pass to nbdkit
by Blake Jiang 22 Oct '26

22 Oct '26

Hello, In the Go plugin bindings, Debug and Error pass a C.CString to the varargs wrappers and never free it (plugins/golang/src/libguestfs.org/nbdkit/utils.go, commit 9af733d0fa3ae7aa5c32f51355185486840f82bc): func Debug(s string) { C._nbdkit_debug(C.CString(s)) } func Error(s string) { C._nbdkit_error(C.CString(s)) } The wrappers in the same file only format the string (nbdkit_debug ("%s", s) / nbdkit_error ("%s", s)), and nbdkit does not keep the pointer, so each call leaves len(s)+1 bytes allocated. C.CString memory is never collected by the Go runtime. Error is also called implicitly by set_error (nbdkit.go) whenever a plugin callback returns a Go error, so a long-running plugin leaks one string per failed callback, plus one per Debug call (the string is allocated even when -v is not given). ParseBool, ParseSize and ReadPassword in the same file already use the usual pattern: With a small test program that copies Debug, Error and the two wrappers, with nbdkit_debug/nbdkit_error replaced by stubs that format into a local buffer, 100000 Debug+Error pairs grew the C heap by about 6.4 MB (64 bytes per pair). With the frees below the growth went away. Suggested change: func Debug(s string) { cs := C.CString(s) defer C.free(unsafe.Pointer(cs)) C._nbdkit_debug(cs) } func Error(s string) { cs := C.CString(s) defer C.free(unsafe.Pointer(cs)) C._nbdkit_error(cs) } If you could credit me as a reporter for my contributions to security advisory I will be thankful. Thanks, Penghao Jiang

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nbdkit | Failed pipeline for master | 607842b2
by GitLab 18 Oct '26

18 Oct '26

Pipeline #2960481327 has failed! Project: nbdkit ( https://gitlab.com/nbdkit/nbdkit ) Branch: master ( https://gitlab.com/nbdkit/nbdkit/-/commits/master ) Commit: 607842b2 ( https://gitlab.com/nbdkit/nbdkit/-/commit/607842b295b3129e1495ee726a84e5936… ) Commit Message: extentlist: Document that nbdinfo --map is comp... Commit Author: Richard W_M_ Jones ( https://gitlab.com/rwmjones ) Pipeline #2960481327 ( https://gitlab.com/nbdkit/nbdkit/-/pipelines/2960481327 ) triggered by Richard W_M_ Jones ( https://gitlab.com/rwmjones ) had 1 failed job. Job #17266340593 ( https://gitlab.com/nbdkit/nbdkit/-/jobs/17266340593/raw ) Stage: builds Name: x86_64-centos-stream-9 -- You're receiving this email because of your account on gitlab.com.

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TEST for ML migration
by Marc Dequènes (duck) 15 Oct '26

15 Oct '26

Quack, This is a test to check the ML after migration, please ignore. Regards. \_o< -- Marc Dequènes

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libnbd | Failed pipeline for master | 7aa21121
by GitLab 10 Oct '26

10 Oct '26

Pipeline #2933063609 has failed! Project: libnbd ( https://gitlab.com/nbdkit/libnbd ) Branch: master ( https://gitlab.com/nbdkit/libnbd/-/commits/master ) Commit: 7aa21121 ( https://gitlab.com/nbdkit/libnbd/-/commit/7aa21121a533b3d373bee040ac0fc966b… ) Commit Message: Merge branch '2026-empty-copy' into 'master' c... Commit Author: Richard W_M_ Jones ( https://gitlab.com/rwmjones ) Pipeline #2933063609 ( https://gitlab.com/nbdkit/libnbd/-/pipelines/2933063609 ) triggered by Richard W_M_ Jones ( https://gitlab.com/rwmjones ) had 1 failed job. Job #17078266545 ( https://gitlab.com/nbdkit/libnbd/-/jobs/17078266545/raw ) Stage: builds Name: x86_64-opensuse-leap-15 -- You're receiving this email because of your account on gitlab.com.

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[libguestfs PATCH] java: free JNI local refs in the event callback
by qiuyucheng 05 Oct '26

05 Oct '26

java_callback allocates a jstring and a jlongArray on every event. The callback runs on the Java thread already inside a JNI native method, so those local refs stay in the outer frame until that method returns. A progress or appliance-log handler can fire often enough in one call to overflow the JNI local reference table. Push a local frame around the callback and pop it after CallVoidMethod returns. Fixes: https://github.com/libguestfs/libguestfs/issues/403 Signed-off-by: qiuyucheng <2847117296(a)qq.com> --- java/handle.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/java/handle.c b/java/handle.c index 629dfd95e..501c09e7f 100644 --- a/java/handle.c +++ b/java/handle.c @@ -155,6 +155,15 @@ java_callback (guestfs_h *g, } } + /* Events run on the Java thread already inside a JNI call, so + * local refs created here stay live until that outer call returns. + */ + if ((*env)->PushLocalFrame (env, 16) < 0) { + (*env)->ExceptionDescribe (env); + (*env)->ExceptionClear (env); + return; + } + /* Convert the buffer and array to Java objects. */ jbuf = (*env)->NewStringUTF (env, buf); // XXX size @@ -175,6 +184,8 @@ java_callback (guestfs_h *g, (*env)->ExceptionDescribe (env); (*env)->ExceptionClear (env); } + + (*env)->PopLocalFrame (env, NULL); } JNIEXPORT jint JNICALL -- 2.33.0

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[libnbd PATCH] fuse: Recommend soft unmount
by Eric Blake 02 Oct '26

02 Oct '26

On some corporate systems, the presence of scanning software tries to make sure that mountpoints are not going to forbidden destinations; this can result in race conditions where a bare fusermount3 -u hits a device still temporarily in use even after libnbd has released things. A lazy unmount solves the problems; I was previously hitting test failures about 60% of test runs, while this one let me do 100 back-to-back runs with no failures. Signed-off-by: Eric Blake <eblake(a)redhat.com> --- fuse/nbdfuse.pod | 14 +++++++------- fuse/test-errors.sh | 2 +- fuse/test-file-mode.sh | 2 +- fuse/test-nbdkit-command.sh | 2 +- fuse/test-nbdkit-file-null.sh | 2 +- fuse/test-nbdkit.sh | 2 +- fuse/test-parallel.sh | 2 +- fuse/test-pattern.sh | 2 +- fuse/test-qcow2.sh | 2 +- fuse/test-trim.sh | 4 ++-- fuse/test-unix.sh | 4 ++-- fuse/test-zero.sh | 4 ++-- 12 files changed, 21 insertions(+), 21 deletions(-) diff --git a/fuse/nbdfuse.pod b/fuse/nbdfuse.pod index 071c4a17..937f826d 100644 --- a/fuse/nbdfuse.pod +++ b/fuse/nbdfuse.pod @@ -35,7 +35,7 @@ nbdfuse - mount a network block device in the local filesystem To unmount: - fusermount3 -u MOUNTPOINT + fusermount3 -u -z MOUNTPOINT Other options: @@ -65,7 +65,7 @@ specified as an NBD URI (like C<nbd://localhost>), or as an NBD server running as a subprocess of nbdfuse (using S<C<[ ... ]>>), or in various other ways (see L</MODES>). -Use C<fusermount3 -u MOUNTPOINT> to unmount the filesystem after you +Use C<fusermount3 -u -z MOUNTPOINT> to unmount the filesystem after you have used it. =head1 EXAMPLES @@ -86,7 +86,7 @@ The file is called F<dir/nbd> and you can read and write to it as if it is a normal file. Note that writes to the file will write to the remote NBD server. After using it, unmount it: - $ fusermount3 -u dir + $ fusermount3 -u -z dir $ rmdir dir =head2 Use nbdkit to create a file backed by a temporary RAM disk @@ -109,7 +109,7 @@ When you have finished with the RAM disk, you can unmount it as below which will cause nbdkit to exit and the RAM disk contents to be discarded: - $ fusermount3 -u dir + $ fusermount3 -u -z dir $ rmdir dir =head2 Use qemu-nbd to read and modify a qcow2 file @@ -127,7 +127,7 @@ File F<dir/file.raw> is in raw format, backed by F<file.qcow2>. Any changes made to F<dir/file.raw> are reflected into the qcow2 file. To unmount the file do: - $ fusermount3 -u dir + $ fusermount3 -u -z dir $ rmdir dir =head2 Use nbdkit to create a local file from a file on a web server @@ -148,7 +148,7 @@ virtual files: dir/disk.iso: DOS/MBR boot sector $ qemu-system-x86_64 -m 4G \ -drive file=dir/disk.iso,format=raw,if=virtio,snapshot=on - $ fusermount3 -u dir + $ fusermount3 -u -z dir In this example we have used the virtual file to boot qemu, but qemu can much more efficiently access NBD servers directly so in the real @@ -226,7 +226,7 @@ Use these options to map UIDs and GIDs. When nbdfuse is ready to serve, write the nbdfuse process ID (PID) to F<PIDFILE>. This can be used in scripts to wait until nbdfuse is -ready. Note you mustn't try to kill nbdfuse. Use C<fusermount3 -u> +ready. Note you mustn't try to kill nbdfuse. Use C<fusermount3 -u -z> to unmount the mountpoint which will cause nbdfuse to exit cleanly. =item B<-r> diff --git a/fuse/test-errors.sh b/fuse/test-errors.sh index 71dd3186..4059aadf 100755 --- a/fuse/test-errors.sh +++ b/fuse/test-errors.sh @@ -38,7 +38,7 @@ fi mp=test-errors.d pidfile=test-errors.pid -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp $pidfile mkdir $mp diff --git a/fuse/test-file-mode.sh b/fuse/test-file-mode.sh index 53ec78c5..87356429 100755 --- a/fuse/test-file-mode.sh +++ b/fuse/test-file-mode.sh @@ -36,7 +36,7 @@ fi pidfile=test-file-mode.pid mp=test-file-mode data=test-file-mode.data -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -f $pidfile $mp $data touch $mp diff --git a/fuse/test-nbdkit-command.sh b/fuse/test-nbdkit-command.sh index 2ff794f3..b958d4b9 100755 --- a/fuse/test-nbdkit-command.sh +++ b/fuse/test-nbdkit-command.sh @@ -36,7 +36,7 @@ fi pidfile=test-nbdkit-command.pid mp=test-nbdkit-command.d data=test-nbdkit-command.data -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp cleanup_fn rm -f $pidfile $data diff --git a/fuse/test-nbdkit-file-null.sh b/fuse/test-nbdkit-file-null.sh index 9103c235..ade6dd8e 100755 --- a/fuse/test-nbdkit-file-null.sh +++ b/fuse/test-nbdkit-file-null.sh @@ -30,7 +30,7 @@ requires $TRUNCATE --version pidfile=test-nbdkit-file-null.pid mp=test-nbdkit-file-null rm -f $pidfile $mp -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -f $pidfile $mp # Create the underlying file/mountpoint as non-zero sized. diff --git a/fuse/test-nbdkit.sh b/fuse/test-nbdkit.sh index 7e193101..6f4637a2 100755 --- a/fuse/test-nbdkit.sh +++ b/fuse/test-nbdkit.sh @@ -36,7 +36,7 @@ fi pidfile=test-nbdkit.pid mp=test-nbdkit.d data=test-nbdkit.data -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp cleanup_fn rm -f $pidfile $data diff --git a/fuse/test-parallel.sh b/fuse/test-parallel.sh index d9136d55..cd072f2f 100755 --- a/fuse/test-parallel.sh +++ b/fuse/test-parallel.sh @@ -37,7 +37,7 @@ fi mp=test-parallel.d pidfile=test-parallel.pid -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp $pidfile mkdir $mp diff --git a/fuse/test-pattern.sh b/fuse/test-pattern.sh index dffcdaff..dbfce132 100755 --- a/fuse/test-pattern.sh +++ b/fuse/test-pattern.sh @@ -41,7 +41,7 @@ fi mp=test-pattern.d out=test-pattern.out pidfile=test-pattern.pid -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp $out $pidfile mkdir $mp diff --git a/fuse/test-qcow2.sh b/fuse/test-qcow2.sh index 3d25f2b2..e9c1753c 100755 --- a/fuse/test-qcow2.sh +++ b/fuse/test-qcow2.sh @@ -39,7 +39,7 @@ pidfile=test-qcow2.pid mp=test-qcow2.d data=test-qcow2.data qcow2=test-qcow2.qcow2 -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp cleanup_fn rm -f $pidfile $data $qcow2 diff --git a/fuse/test-trim.sh b/fuse/test-trim.sh index 04ec41ab..dc4d9b9a 100755 --- a/fuse/test-trim.sh +++ b/fuse/test-trim.sh @@ -39,7 +39,7 @@ fi mp=test-trim.d pidfile=test-trim.pid out=test-trim.out -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp $pidfile $out mkdir $mp @@ -75,7 +75,7 @@ fallocate -p -l 512 -o 512 $mp/nbd # We have to explicitly unmount it here else nbdfuse will # never exit and nbdkit will hang. -fusermount3 -u $mp +fusermount3 -u -z $mp ' <<'EOF' # The nbdkit server script. case "$1" in diff --git a/fuse/test-unix.sh b/fuse/test-unix.sh index 43d2b890..b6a5a25d 100755 --- a/fuse/test-unix.sh +++ b/fuse/test-unix.sh @@ -35,7 +35,7 @@ fi mp=test-unix.d pidfile=test-unix.pid -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp $pidfile mkdir $mp @@ -62,5 +62,5 @@ $NBDKIT -U - null --run ' # We have to explicitly unmount it here else nbdfuse will # never exit and nbdkit will hang. - fusermount3 -u $mp + fusermount3 -u -z $mp ' diff --git a/fuse/test-zero.sh b/fuse/test-zero.sh index a95680b7..81a307e3 100755 --- a/fuse/test-zero.sh +++ b/fuse/test-zero.sh @@ -42,7 +42,7 @@ fi mp=test-zero.d pidfile=test-zero.pid out=test-zero.out -cleanup_fn fusermount3 -u $mp +cleanup_fn fusermount3 -u -z $mp cleanup_fn rm -rf $mp $pidfile $out mkdir $mp @@ -78,7 +78,7 @@ fallocate -z -l 512 -o 512 $mp/nbd # We have to explicitly unmount it here else nbdfuse will # never exit and nbdkit will hang. -fusermount3 -u $mp +fusermount3 -u -z $mp ' <<'EOF' # The nbdkit server script. case "$1" in -- 2.55.0

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