syzbot has found a reproducer for the following issue on: HEAD commit: 764822972d64 Merge tag 'nfsd-6.2' of git://git.kernel.org/.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=1428fb0b880000 kernel config: https://syzkaller.appspot.com/x/.config?x=8c59170b68d26a55 dashboard link: https://syzkaller.appspot.com/bug?extid=ececff266234ba40fe13 compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14ce69c0480000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1016950b880000
Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/0c840c19749d/disk-76482297.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/bdfd51618ae0/vmlinux-76482297.xz kernel image: https://storage.googleapis.com/syzbot-assets/fef17b5d4d6d/bzImage-76482297.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/a114b1cb5db6/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ececff266234ba40f...@syzkaller.appspotmail.com general protection fault, probably for non-canonical address 0xdffffc0000000097: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000004b8-0x00000000000004bf] CPU: 1 PID: 1273 Comm: kworker/1:1H Not tainted 6.1.0-syzkaller-03225-g764822972d64 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: glock_workqueue glock_work_func RIP: 0010:is_system_glock fs/gfs2/glock.c:725 [inline] RIP: 0010:do_xmote+0xdde/0x13d0 fs/gfs2/glock.c:835 Code: 00 48 03 5d 00 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 91 e1 27 fe bd b8 04 00 00 48 03 2b 48 89 e8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 ef e8 73 e1 27 fe 4c 8b 64 24 08 4c 39 RSP: 0018:ffffc900061a7b70 EFLAGS: 00010202 RAX: 0000000000000097 RBX: ffff888021dd8718 RCX: ffff888021c93a80 RDX: 0000000000000000 RSI: 0000000000004000 RDI: 0000000000000000 RBP: 00000000000004b8 R08: ffffffff83b7d986 R09: ffffed10043bb016 R10: ffffed10043bb016 R11: 1ffff110043bb015 R12: ffff888075bf0548 R13: 0000000000000818 R14: dffffc0000000000 R15: ffff888021dd8000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002080 CR3: 000000007a61b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> glock_work_func+0x2c2/0x450 fs/gfs2/glock.c:1082 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:is_system_glock fs/gfs2/glock.c:725 [inline] RIP: 0010:do_xmote+0xdde/0x13d0 fs/gfs2/glock.c:835 Code: 00 48 03 5d 00 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 91 e1 27 fe bd b8 04 00 00 48 03 2b 48 89 e8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 ef e8 73 e1 27 fe 4c 8b 64 24 08 4c 39 RSP: 0018:ffffc900061a7b70 EFLAGS: 00010202 RAX: 0000000000000097 RBX: ffff888021dd8718 RCX: ffff888021c93a80 RDX: 0000000000000000 RSI: 0000000000004000 RDI: 0000000000000000 RBP: 00000000000004b8 R08: ffffffff83b7d986 R09: ffffed10043bb016 R10: ffffed10043bb016 R11: 1ffff110043bb015 R12: ffff888075bf0548 R13: 0000000000000818 R14: dffffc0000000000 R15: ffff888021dd8000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002080 CR3: 000000007e6e4000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 00 48 03 add %cl,0x3(%rax) 3: 5d pop %rbp 4: 00 48 89 add %cl,-0x77(%rax) 7: d8 48 c1 fmuls -0x3f(%rax) a: e8 03 42 80 3c callq 0x3c804212 f: 30 00 xor %al,(%rax) 11: 74 08 je 0x1b 13: 48 89 df mov %rbx,%rdi 16: e8 91 e1 27 fe callq 0xfe27e1ac 1b: bd b8 04 00 00 mov $0x4b8,%ebp 20: 48 03 2b add (%rbx),%rbp 23: 48 89 e8 mov %rbp,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 ef mov %rbp,%rdi 34: e8 73 e1 27 fe callq 0xfe27e1ac 39: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 3e: 4c rex.WR 3f: 39 .byte 0x39
