Hello, syzbot found the following issue on:
HEAD commit: e72e9e693307 Merge tag 'net-6.15-rc4' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11ef21b3980000 kernel config: https://syzkaller.appspot.com/x/.config?x=4f9c44a22d09fd53 dashboard link: https://syzkaller.appspot.com/bug?extid=14c52d86ddbd89bea13e compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11777d9b980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15ef21b3980000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-e72e9e69.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/2bee8b8591c3/vmlinux-e72e9e69.xz kernel image: https://storage.googleapis.com/syzbot-assets/97a6564905c3/bzImage-e72e9e69.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/067449ccbbaf/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: [email protected] bcachefs (loop0): bucket 0:26 gen 0 data type btree sector count overflow: 0 + -256 > U32_MAX while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq ac62141f8dc7e261 written 24 min_key POS_MIN durability: 1 ptr: 0:26:0 gen 0 ------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in fs/bcachefs/sb-downgrade.c:268:4 index 0 is out of range for type '__le16[] __counted_by(nr_errors)' (aka 'unsigned short[]') CPU: 0 UID: 0 PID: 1037 Comm: kworker/u4:6 Not tainted 6.15.0-rc3-syzkaller-00076-ge72e9e693307 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: btree_update btree_interior_update_work Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 ubsan_epilogue+0xa/0x40 lib/ubsan.c:231 __ubsan_handle_out_of_bounds+0xe9/0xf0 lib/ubsan.c:453 downgrade_table_extra fs/bcachefs/sb-downgrade.c:268 [inline] bch2_sb_downgrade_update+0xb10/0xcc0 fs/bcachefs/sb-downgrade.c:388 bch2_write_super+0xbf4/0x2cc0 fs/bcachefs/super-io.c:1071 btree_update_new_nodes_mark_sb fs/bcachefs/btree_update_interior.c:608 [inline] btree_update_nodes_written fs/bcachefs/btree_update_interior.c:678 [inline] btree_interior_update_work+0x441/0x25e0 fs/bcachefs/btree_update_interior.c:843 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> ---[ end trace ]--- Kernel panic - not syncing: UBSAN: panic_on_warn set ... CPU: 0 UID: 0 PID: 1037 Comm: kworker/u4:6 Not tainted 6.15.0-rc3-syzkaller-00076-ge72e9e693307 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: btree_update btree_interior_update_work Call Trace: <TASK> dump_stack_lvl+0x99/0x250 lib/dump_stack.c:120 panic+0x2db/0x790 kernel/panic.c:354 check_panic_on_warn+0x89/0xb0 kernel/panic.c:243 __ubsan_handle_out_of_bounds+0xe9/0xf0 lib/ubsan.c:453 downgrade_table_extra fs/bcachefs/sb-downgrade.c:268 [inline] bch2_sb_downgrade_update+0xb10/0xcc0 fs/bcachefs/sb-downgrade.c:388 bch2_write_super+0xbf4/0x2cc0 fs/bcachefs/super-io.c:1071 btree_update_new_nodes_mark_sb fs/bcachefs/btree_update_interior.c:608 [inline] btree_update_nodes_written fs/bcachefs/btree_update_interior.c:678 [inline] btree_interior_update_work+0x441/0x25e0 fs/bcachefs/btree_update_interior.c:843 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Kernel Offset: disabled Rebooting in 86400 seconds.. --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at [email protected]. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
