** Description changed: + [ Impact ] + + * An explanation of the effects of the bug on users and justification + for backporting the fix to the stable release. + + * In addition, it is helpful, but not required, to include an + explanation of how the upload fixes this bug. + + [ Test Plan ] + + * detailed instructions how to reproduce the bug + + * these should allow someone who is not familiar with the affected + package to reproduce the bug and verify that the updated package + fixes the problem. + + * if other testing is appropriate to perform before landing this + update, this should also be described here. + + [ Where problems could occur ] + + * Think about what the upload changes in the software. Imagine the + change is wrong or breaks something else: how would this show up? + + * It is assumed that any SRU candidate patch is well-tested before + upload and has a low overall risk of regression, but it's important + to make the effort to think about what ''could'' happen in the event + of a regression. + + * This must never be "None" or "Low", or entirely an argument as to why + your upload is low risk. + + * This both shows the SRU team that the risks have been considered, + and provides guidance to testers in regression-testing the SRU. + + [ Other Info ] + + * Anything else you think is useful to include + + * Make sure to explain any deviation from the norm, to save the SRU + reviewer from having to infer your reasoning, possibly incorrectly. + This should also help reduce review iterations, particularly when the + reason for the deviation is not obvious. + + * Anticipate questions from users, SRU, +1 maintenance, security teams + and the Technical Board and address these questions in advance + + [ Original Description ] + **Package:** samba **Ubuntu:** 24.04.4 LTS (Noble) **Architecture:** amd64 **Installed version:** `2:4.19.5+dfsg-4ubuntu9.7` ### Problem Samba in Ubuntu 24.04.4 LTS still uses Samba 4.19.5, reproduces upstream SAMBA Bug 15527 (https://bugzilla.samba.org/show_bug.cgi?id=15527) when an SMB share is backed by a mergerfs/FUSE filesystem. I have a share at `/mnt/data`, which is: ``` /mnt/data mergerfs fuse.mergerfs rw,...,allow_other ``` A SKYBOX VR client connects over SMB and can browse and play files normally. When it attempts to delete a file: 1. The file is actually deleted from the filesystem. 2. Samba returns `NT_STATUS_ACCESS_DENIED` during SMB2 CLOSE. 3. `smbd` then hits the `fd_handle_destructor()` assertion and panics. 4. SKYBOX reports "Failed to delete", although the file has already disappeared. The relevant stock Samba 4.19.5 log was: ``` ratcliffes opened file media/TV Shows/The Wonder Years/aaa.jpg read=No write=No ratcliffes closed file media/TV Shows/The Wonder Years/aaa.jpg (numopen=0) NT_STATUS_ACCESS_DENIED PANIC: assert failed at source3/smbd/fd_handle.c (fh->fd == -1) || (fh->fd == AT_FDCWD) ``` This corresponds directly to upstream SAMBA Bug 15527, which is documented as: ``` fd_handle_destructor() panics within an smbd_smb2_close() if vfs_stat_fsp() fails in fd_close() ``` The bug was fixed upstream in Samba 4.19.6. ### Verification I built Ubuntu's existing 4.19.5+dfsg-4ubuntu9.7 source package with the upstream SAMBA Bug 15527 fix applied, retaining Ubuntu's existing patch stack. The fix consists of the two upstream changes to `close.c` and `open.c`, including resetting: ``` fsp->fsp_flags.fstat_before_close = false; ``` and ensuring the file descriptor is closed even when `vfs_stat_fsp()` fails. I installed the resulting packages and repeated the exact same SKYBOX deletion test. **Result:** the file was deleted successfully and SKYBOX reported successful deletion. There was no `fd_handle_destructor` assertion or smbd panic. ### Request Please consider backporting the upstream Samba 4.19.6 Bug 15527 fix into the Ubuntu 24.04.4 LTS Samba package. This appears particularly relevant to users using Samba shares backed by FUSE filesystems such as mergerfs... especially because this is a prominent bug in an LTS release. Upstream Samba 4.19.6 release notes identify SAMBA Bug 15527 as fixed: https://www.samba.org/samba/history/samba-4.19.6.html The current Noble package remains 4.19.5: `2:4.19.5+dfsg-4ubuntu9.7`
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2166678 Title: Samba 4.19.5 in Ubuntu 24.04.4 LTS hits upstream Bug 15527 with mergerfs/FUSE, causing SMB2 CLOSE failure and smbd panic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/samba/+bug/2166678/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
