On Sat, May 31, 2025 at 11:06:28PM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 4cb6c8af8591 selftests/filesystems: Fix build of anon_inod.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=16a8a00c580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=43b7075a5c42ffca > dashboard link: https://syzkaller.appspot.com/bug?extid=56edda805363e0a093b8 > compiler: Debian clang version 20.1.6 > (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11c67ed4580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=147a300c580000 > > Downloadable assets: > disk image (non-bootable): > https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-4cb6c8af.raw.xz > vmlinux: > https://storage.googleapis.com/syzbot-assets/91b28032d866/vmlinux-4cb6c8af.xz > kernel image: > https://storage.googleapis.com/syzbot-assets/7cf2a9f8c096/bzImage-4cb6c8af.xz > mounted in repro #1: > https://storage.googleapis.com/syzbot-assets/9c0eef7ba9b5/mount_0.gz > mounted in repro #2: > https://storage.googleapis.com/syzbot-assets/0c5386ea7a4e/mount_4.gz > fsck result: failed (log: > https://syzkaller.appspot.com/x/fsck.log?x=12a8a00c580000) > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: [email protected] > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > #PF: supervisor instruction fetch in kernel mode > #PF: error_code(0x0010) - not-present page > PGD 0 P4D 0 > Oops: Oops: 0010 [#1] SMP KASAN NOPTI > CPU: 0 UID: 0 PID: 5317 Comm: syz-executor257 Not tainted > 6.15.0-syzkaller-10402-g4cb6c8af8591 #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 > RIP: 0010:0x0 > Code: Unable to access opcode bytes at 0xffffffffffffffd6. > RSP: 0018:ffffc9000d3fedb8 EFLAGS: 00010246 > RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888044583ee8 > RDX: 1ffff110088b07dd RSI: 0000000000000000 RDI: 0000000000092800 > RBP: ffffc9000d3fef10 R08: ffffc9000d3fee87 R09: 0000000000000000 > R10: ffffc9000d3fee60 R11: 0000000000000000 R12: 1ffff92001a7fdc8 > R13: ffff888044583ee8 R14: 0000000000092c40 R15: 0000000000092800 > FS: 0000000000000000(0000) GS:ffff88808d265000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffd6 CR3: 0000000042a6b000 CR4: 0000000000352ef0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > mempool_alloc_noprof+0x1a7/0x510 mm/mempool.c:402 > bch2_btree_update_start+0x549/0x1480 fs/bcachefs/btree_update_interior.c:1194 > bch2_btree_node_rewrite+0x17e/0x1120 fs/bcachefs/btree_update_interior.c:2208 > bch2_move_btree+0x6f0/0xc70 fs/bcachefs/move.c:1093 > bch2_scan_old_btree_nodes+0x95/0x240 fs/bcachefs/move.c:1215 > bch2_data_job+0x646/0x910 fs/bcachefs/move.c:1354 > bch2_data_thread+0x8f/0x1d0 fs/bcachefs/chardev.c:315 > kthread+0x711/0x8a0 kernel/kthread.c:464 > ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 > </TASK> > Modules linked in: > CR2: 0000000000000000 > ---[ end trace 0000000000000000 ]--- > RIP: 0010:0x0 > Code: Unable to access opcode bytes at 0xffffffffffffffd6. > RSP: 0018:ffffc9000d3fedb8 EFLAGS: 00010246 > RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888044583ee8 > RDX: 1ffff110088b07dd RSI: 0000000000000000 RDI: 0000000000092800 > RBP: ffffc9000d3fef10 R08: ffffc9000d3fee87 R09: 0000000000000000 > R10: ffffc9000d3fee60 R11: 0000000000000000 R12: 1ffff92001a7fdc8 > R13: ffff888044583ee8 R14: 0000000000092c40 R15: 0000000000092800 > FS: 0000000000000000(0000) GS:ffff88808d265000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffd6 CR3: 0000000042a6b000 CR4: 0000000000352ef0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > 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
#syz fix: bcachefs: Fix pool->alloc NULL pointer dereference
