Debian Buster segfaults after migration #12141

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opened 2026-02-21 22:22:47 -05:00 by deekerman · 2 comments

deekerman commented

2026-02-21 22:22:47 -05:00

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Originally created by @ljmc-github on GitHub (May 18, 2021).

Please provide the following information

qBittorrent version and Operating System

qbittorrent-nox/stable,stable,now 4.1.5-1+deb10u1 amd64 [installed]
OS: Debian Buster 10.8 fresh install

If on linux, libtorrent-rasterbar and Qt version

libtorrent-rasterbar9/stable,now 1.1.11-2 amd64 [installed,automatic]
libqt5core5a/stable,now 5.11.3+dfsg1-1+deb10u4 amd64 [installed,automatic]

What is the problem

Migrating from Centos host (v4.2.5) to Debian VM (v4.1.5), copied the BT_backup and necessary part of qBittorrent.conf.
Launched as a service the web-ui seemed to be very unstable, could authenticate then within 1-2 seconds, I got the "qBittorrent client is not reachable".
Further investigation, logs are filled with lines like:

(C) 2021-05-18T23:31:21 - Fast resume data was rejected for torrent 'FreeBSD-12.2-RELEASE-amd64-dvd1.iso.xz'. Reason: FreeBSD-12.2-RELEASE-amd64-dvd1.iso.xz fast resume rejected. check resume(): missing or invalid 'file sizes' entry. Checking again...

Reduced number of .fastresume and accompanying .torrent files.
su'ed to the reserved user qbtuser.
Launched qbittorrent-nox manually, it segfaults, output in Extra info.
I have not tested service without Restart=on-failure, can update with this information if relevant.

What is the expected behavior

Should not segfault or error fastresume files.

Steps to reproduce

Install debian 10.8
apt update && apt install qbittorrent-nox
mount nfs share
add a few fastresumes from v4.2.5 (might affect other versions)
copy config if necessary
launch qbittorrent-nox

Extra info(if any)

qBittorrent version: v4.1.5

Caught signal: SIGSEGV
Stack trace:
  /lib/x86_64-linux-gnu/libQt5Network.so.5 : ()+0x95b84  [0x7f6352ac7b84]
  /lib/x86_64-linux-gnu/libQt5Network.so.5 : ()+0x94c49  [0x7f6352ac6c49]
  /lib/x86_64-linux-gnu/libQt5Core.so.5 : QObject::event(QEvent*)+0xe2  [0x7f635278c072]
  /lib/x86_64-linux-gnu/libQt5Core.so.5 : QCoreApplication::notifyInternal2(QObject*, QEvent*)+0x156  [0x7f6352762466]
  /lib/x86_64-linux-gnu/libQt5Core.so.5 : QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*)+0x1cb  [0x7f635276546b]
  /lib/x86_64-linux-gnu/libQt5Core.so.5 : ()+0x2bc103  [0x7f63527b4103]
  /lib/x86_64-linux-gnu/libglib-2.0.so.0 : g_main_context_dispatch()+0x2ae  [0x7f6351641f2e]
  /lib/x86_64-linux-gnu/libglib-2.0.so.0 : ()+0x4e1c8  [0x7f63516421c8]
  /lib/x86_64-linux-gnu/libglib-2.0.so.0 : g_main_context_iteration()+0x2c  [0x7f635164225c]
  /lib/x86_64-linux-gnu/libQt5Core.so.5 : QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)+0x67  [0x7f63527b3727]
  /lib/x86_64-linux-gnu/libQt5Core.so.5 : QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)+0x13b  [0x7f635276115b]
  /lib/x86_64-linux-gnu/libQt5Core.so.5 : QThread::exec()+0xb6  [0x7f63525b0e76]
  /lib/x86_64-linux-gnu/libQt5Core.so.5 : ()+0xc2a67  [0x7f63525baa67]
  /lib/x86_64-linux-gnu/libpthread.so.0 : ()+0x7fa3  [0x7f63524dcfa3]
  /lib/x86_64-linux-gnu/libc.so.6 : clone()+0x3f  [0x7f63520ec4cf]
Segmentation fault

Originally created by @ljmc-github on GitHub (May 18, 2021). **Please provide the following information** ### qBittorrent version and Operating System qbittorrent-nox/stable,stable,now 4.1.5-1+deb10u1 amd64 [installed] OS: Debian Buster 10.8 fresh install ### If on linux, libtorrent-rasterbar and Qt version libtorrent-rasterbar9/stable,now 1.1.11-2 amd64 [installed,automatic] libqt5core5a/stable,now 5.11.3+dfsg1-1+deb10u4 amd64 [installed,automatic] ### What is the problem Migrating from Centos host (v4.2.5) to Debian VM (v4.1.5), copied the BT_backup and necessary part of qBittorrent.conf. Launched as a service the web-ui seemed to be very unstable, could authenticate then within 1-2 seconds, I got the "qBittorrent client is not reachable". Further investigation, logs are filled with lines like: ``` (C) 2021-05-18T23:31:21 - Fast resume data was rejected for torrent 'FreeBSD-12.2-RELEASE-amd64-dvd1.iso.xz'. Reason: FreeBSD-12.2-RELEASE-amd64-dvd1.iso.xz fast resume rejected. check resume(): missing or invalid 'file sizes' entry. Checking again... ``` Reduced number of .fastresume and accompanying .torrent files. su'ed to the reserved user qbtuser. Launched qbittorrent-nox manually, it segfaults, output in Extra info. I have not tested service without `Restart=on-failure`, can update with this information if relevant. ### What is the expected behavior Should not segfault or error fastresume files. ### Steps to reproduce 1. Install debian 10.8 2. apt update && apt install qbittorrent-nox 3. mount nfs share 4. add a few fastresumes from v4.2.5 (might affect other versions) 5. copy config if necessary 6. launch qbittorrent-nox ### Extra info(if any) ``` qBittorrent version: v4.1.5 Caught signal: SIGSEGV Stack trace: /lib/x86_64-linux-gnu/libQt5Network.so.5 : ()+0x95b84 [0x7f6352ac7b84] /lib/x86_64-linux-gnu/libQt5Network.so.5 : ()+0x94c49 [0x7f6352ac6c49] /lib/x86_64-linux-gnu/libQt5Core.so.5 : QObject::event(QEvent*)+0xe2 [0x7f635278c072] /lib/x86_64-linux-gnu/libQt5Core.so.5 : QCoreApplication::notifyInternal2(QObject*, QEvent*)+0x156 [0x7f6352762466] /lib/x86_64-linux-gnu/libQt5Core.so.5 : QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*)+0x1cb [0x7f635276546b] /lib/x86_64-linux-gnu/libQt5Core.so.5 : ()+0x2bc103 [0x7f63527b4103] /lib/x86_64-linux-gnu/libglib-2.0.so.0 : g_main_context_dispatch()+0x2ae [0x7f6351641f2e] /lib/x86_64-linux-gnu/libglib-2.0.so.0 : ()+0x4e1c8 [0x7f63516421c8] /lib/x86_64-linux-gnu/libglib-2.0.so.0 : g_main_context_iteration()+0x2c [0x7f635164225c] /lib/x86_64-linux-gnu/libQt5Core.so.5 : QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)+0x67 [0x7f63527b3727] /lib/x86_64-linux-gnu/libQt5Core.so.5 : QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)+0x13b [0x7f635276115b] /lib/x86_64-linux-gnu/libQt5Core.so.5 : QThread::exec()+0xb6 [0x7f63525b0e76] /lib/x86_64-linux-gnu/libQt5Core.so.5 : ()+0xc2a67 [0x7f63525baa67] /lib/x86_64-linux-gnu/libpthread.so.0 : ()+0x7fa3 [0x7f63524dcfa3] /lib/x86_64-linux-gnu/libc.so.6 : clone()+0x3f [0x7f63520ec4cf] Segmentation fault ```

deekerman

2026-02-21 22:22:47 -05:00

closed this issue
added the
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deekerman commented

2026-02-21 22:22:54 -05:00

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Owner

@ljmc-github commented on GitHub (May 19, 2021):

Here you can see what is happening, qBittorrent clearly fails, but luckily still managed to fully check some of the files on retries, every failure adds 'Fast resume data was rejected for torrent' lines for the unchecked files in the log.

All these fastresume and torrent files were checksumed to make sure they're the same on both hosts.

https://user-images.githubusercontent.com/26164870/118797595-0e0c5e80-b89d-11eb-9323-9f74b7a26cc5.mp4

@ljmc-github commented on GitHub (May 19, 2021): Here you can see what is happening, qBittorrent clearly fails, but luckily still managed to fully check some of the files on retries, every failure adds 'Fast resume data was rejected for torrent' lines for the unchecked files in the log. All these fastresume and torrent files were checksumed to make sure they're the same on both hosts. https://user-images.githubusercontent.com/26164870/118797595-0e0c5e80-b89d-11eb-9323-9f74b7a26cc5.mp4

deekerman commented

2026-02-21 22:22:57 -05:00

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Owner

@thalieht commented on GitHub (May 19, 2021):

qBittorrent version: v4.1.5

Caught signal: SIGSEGV

Too old and probably a duplicate of #9667 which was fixed long ago.

@thalieht commented on GitHub (May 19, 2021): >qBittorrent version: v4.1.5 > >Caught signal: SIGSEGV Too old and probably a duplicate of #9667 which was fixed long ago.