Hi Luca, Yes, I also think you are seeing the exact same issue. The WARN_ON was introduced in the following commit:
ubuntu-noble b2ad25ba539452f492805e5f7d94e80894aa860f commit a776bf5f3c2300cfdf8a195663460b1793ac9847 Author: Qu Wenruo <w...@suse.com> Date: Fri Apr 19 14:29:32 2024 +0930 Subject: btrfs: slightly loosen the requirement for qgroup removal Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a776bf5f3c2300cfdf8a195663460b1793ac9847 $ git describe --contains b2ad25ba539452f492805e5f7d94e80894aa860f Ubuntu-6.8.0-50.51~143 This doesn't exactly panic the kernel as you say, it outputs a warning to dmesg. You seem to have the sysctl panic_on_warn set, and that's what panics the system. For now use 6.8.0-49-generic or turn off panic_on_warn as a workaround until this gets fixed. Now the commit: btrfs-devel c61ffaa0a3d9a2094e24d1fe2b17f20e109d2cc8 Author: Qu Wenruo <w...@suse.com> Date: Mon Nov 11 07:29:07 2024 +1030 Subject: btrfs: improve the warning and error message for btrfs_remove_qgroup() Link: https://github.com/btrfs/linux/commit/c61ffaa0a3d9a2094e24d1fe2b17f20e109d2cc8 This hasn't been merged into mainline just yet, it is still in the btrfs devel tree. We need to wait until it reaches Linus's tree before we can merge into Ubuntu. For the mean time, if you like, I made a test kernel based on 6.8.0-50-generic for 24.04 with the commit applied if you want to test it out to see if it fixes your problem. Please note this package is NOT SUPPORTED by Canonical, and is for TESTING PURPOSES ONLY. ONLY Install in a dedicated test environment. Instructions to Install (On a mantic system): 1) sudo add-apt-repository ppa:mruffell/lp2091719-test 2) sudo apt update 3) sudo apt install linux-image-unsigned-6.8.0-50-generic linux-modules-6.8.0-50-generic linux-modules-extra-6.8.0-50-generic linux-headers-6.8.0-50-generic 4) sudo reboot 5) uname -rv 6.8.0-50-generic #51+TEST2091719v20241216b1-Ubuntu SMP PREEMPT_DYNAMIC Sun Dec 15 Again, if it works, we will wait until it reaches mainline, and then we can begin the SRU process. Thanks, Matthew -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2091719 Title: BTRFS kernel panic on btrfs_remove_qgroup Status in linux package in Ubuntu: Confirmed Status in linux source package in Noble: Confirmed Bug description: We are able to trigger a kernel oops in the btrfs code from userspace: [ 46.597006] Kernel panic - not syncing: kernel: panic_on_warn set ... [ 46.597474] CPU: 0 PID: 1316 Comm: (sd-clean) Not tainted 6.8.0-50-generic #51-Ubuntu [ 46.597660] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-3.fc41 04/01/2014 [ 46.597882] Call Trace: [ 46.597948] <TASK> [ 46.598028] dump_stack_lvl+0x27/0xa0 [ 46.598115] dump_stack+0x10/0x20 [ 46.598222] panic+0x366/0x3c0 [ 46.598319] ? btrfs_remove_qgroup+0x271/0x490 [btrfs] [ 46.598517] check_panic_on_warn+0x4f/0x60 [ 46.598609] __warn+0x95/0x160 [ 46.598703] ? btrfs_remove_qgroup+0x271/0x490 [btrfs] [ 46.598932] report_bug+0x17e/0x1b0 [ 46.599245] handle_bug+0x51/0xa0 [ 46.599414] exc_invalid_op+0x18/0x80 [ 46.599645] asm_exc_invalid_op+0x1b/0x20 [ 46.599794] RIP: 0010:btrfs_remove_qgroup+0x271/0x490 [btrfs] [ 46.600073] Code: c0 0f 85 27 fe ff ff 48 8b 43 b0 4c 39 f0 75 d5 4d 8d b5 e0 08 00 00 4c 89 f7 e8 8a 45 19 e2 48 83 7b 98 00 0f 84 52 01 00 00 <0f> 0b 49 8b 45 10 a8 10 74 42 41 f6 85 d0 08 00 00 0c 75 38 48 83 [ 46.600516] RSP: 0018:ffffa0a0c30b3d58 EFLAGS: 00010206 [ 46.600640] RAX: 0000000000000000 RBX: ffff958787663cb8 RCX: 0000000000000000 [ 46.600826] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 46.601025] RBP: ffffa0a0c30b3dc0 R08: 0000000000000000 R09: 0000000000000000 [ 46.601199] R10: 0000000000000000 R11: 0000000000000000 R12: 00ff00000000010f [ 46.601385] R13: ffff95878b730000 R14: ffff95878b7308e0 R15: 0000000000000000 [ 46.601579] ? btrfs_remove_qgroup+0x266/0x490 [btrfs] [ 46.601867] btrfs_ioctl+0x12b9/0x13a0 [btrfs] [ 46.602100] ? srso_alias_return_thunk+0x5/0xfbef5 [ 46.602575] ? __seccomp_filter+0x368/0x570 [ 46.602696] ? __fput+0x15e/0x2e0 [ 46.602993] __x64_sys_ioctl+0xa3/0xf0 [ 46.603143] x64_sys_call+0x12a3/0x25a0 [ 46.603379] do_syscall_64+0x7f/0x180 [ 46.603557] ? srso_alias_return_thunk+0x5/0xfbef5 [ 46.603680] ? do_syscall_64+0x8c/0x180 [ 46.603774] ? srso_alias_return_thunk+0x5/0xfbef5 [ 46.603898] ? syscall_exit_to_user_mode+0x86/0x260 [ 46.604043] ? srso_alias_return_thunk+0x5/0xfbef5 [ 46.604155] ? do_syscall_64+0x8c/0x180 [ 46.604248] ? do_syscall_64+0x8c/0x180 [ 46.604341] ? srso_alias_return_thunk+0x5/0xfbef5 [ 46.604693] entry_SYSCALL_64_after_hwframe+0x78/0x80 [ 46.605029] RIP: 0033:0x7c2fbeb24ded [ 46.605283] Code: 04 25 28 00 00 00 48 89 45 c8 31 c0 48 8d 45 10 c7 45 b0 10 00 00 00 48 89 45 b8 48 8d 45 d0 48 89 45 c0 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1a 48 8b 45 c8 64 48 2b 04 25 28 00 00 00 [ 46.606374] RSP: 002b:00007ffe3e103770 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 46.607365] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007c2fbeb24ded [ 46.607872] RDX: 00007ffe3e1037d0 RSI: 000000004010942a RDI: 0000000000000016 [ 46.608856] RBP: 00007ffe3e1037c0 R08: 0000000000000069 R09: 0000000000000000 [ 46.609477] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016 [ 46.609672] R13: 0000000000000000 R14: 00ff00000000010f R15: 0000000000000016 [ 46.609862] </TASK> [ 46.611054] Kernel Offset: 0x20600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) This happens on Ubuntu Noble since the kernel update to 6.8.0-50-generic which was promoted from proposed to updates this week, it did not happen before. The upstream systemd CI on Github reproduces this issue consistently, e.g.: https://github.com/systemd/systemd/actions/runs/12297539029/job/34318915884?pr=35589 It also happens on the newest upstream kernel, and was reproduced with the same backtrace on Archlinux too. It was bisected to one of the following upstream BTRFS commits listed in this Github comment: https://github.com/systemd/systemd/pull/35567#issuecomment-2538160543 A fix has been proposed by SUSE and tested on Archlinux, and confirmed to solve the crash: https://github.com/btrfs/linux/commit/c61ffaa0a3d9a2094e24d1fe2b17f20e109d2cc8 Note that this fix has been tested on Archlinux, not on Ubuntu. But we are confident it's the same issue. 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