Hello, syzbot found the following issue on: HEAD commit: 14240d4c Add linux-next specific files for 20201210 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1321cf17500000 kernel config: https://syzkaller.appspot.com/x/.config?x=6dbe20fdaa5aaebe dashboard link: https://syzkaller.appspot.com/bug?extid=ba2e91df8f74809417fa compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=174ecb9b500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14ff9413500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ba2e91df8f74809417fa@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================================ UBSAN: shift-out-of-bounds in net/sunrpc/xprt.c:658:14 shift exponent 536871232 is too large for 64-bit type 'long unsigned int' CPU: 1 PID: 8494 Comm: syz-executor211 Not tainted 5.10.0-rc7-next-20201210-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:395 xprt_calc_majortimeo.isra.0.cold+0x17/0x46 net/sunrpc/xprt.c:658 xprt_init_majortimeo net/sunrpc/xprt.c:686 [inline] xprt_request_init+0x486/0x9e0 net/sunrpc/xprt.c:1805 xprt_do_reserve net/sunrpc/xprt.c:1815 [inline] xprt_reserve+0x18f/0x280 net/sunrpc/xprt.c:1836 __rpc_execute+0x21d/0x1360 net/sunrpc/sched.c:891 rpc_execute+0x230/0x350 net/sunrpc/sched.c:967 rpc_run_task+0x5d0/0x8f0 net/sunrpc/clnt.c:1140 rpc_call_sync+0xc6/0x1a0 net/sunrpc/clnt.c:1169 rpc_ping net/sunrpc/clnt.c:2682 [inline] rpc_create_xprt+0x3f1/0x4a0 net/sunrpc/clnt.c:477 rpc_create+0x354/0x670 net/sunrpc/clnt.c:593 nfs_create_rpc_client+0x4eb/0x680 fs/nfs/client.c:536 nfs_init_client fs/nfs/client.c:653 [inline] nfs_init_client+0x6d/0x100 fs/nfs/client.c:640 nfs_get_client+0xcd7/0x1020 fs/nfs/client.c:430 nfs_init_server.isra.0+0x2c0/0xed0 fs/nfs/client.c:692 nfs_create_server+0x18f/0x650 fs/nfs/client.c:996 nfs_try_get_tree+0x181/0x9f0 fs/nfs/super.c:939 nfs_get_tree+0xaa1/0x1520 fs/nfs/fs_context.c:1350 vfs_get_tree+0x89/0x2f0 fs/super.c:1496 do_new_mount fs/namespace.c:2896 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3227 do_mount fs/namespace.c:3240 [inline] __do_sys_mount fs/namespace.c:3448 [inline] __se_sys_mount fs/namespace.c:3425 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3425 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x440419 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe282dde28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 0000000000440419 RDX: 0000000020fb5ffc RSI: 0000000020343ff8 RDI: 0000000020000100 RBP: 00000000006ca018 R08: 000000002000a000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401c20 R13: 0000000000401cb0 R14: 0000000000000000 R15: 0000000000000000 ================================================================================ --- 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 syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
