================================================================================ UBSAN: shift-out-of-bounds in net/atm/common.c:389:10 shift exponent -1 is negative CPU: 1 PID: 4433 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 ubsan_epilogue+0xa/0x30 lib/ubsan.c:151 __ubsan_handle_shift_out_of_bounds+0x364/0x3f0 lib/ubsan.c:321 __vcc_connect+0x11b7/0x1600 net/atm/common.c:389 vcc_connect+0x31f/0x880 net/atm/common.c:510 pvc_bind+0x262/0x370 net/atm/pvc.c:52 __sys_bind+0x2e9/0x3e0 net/socket.c:1811 __do_sys_bind net/socket.c:1822 [inline] __se_sys_bind net/socket.c:1820 [inline] __x64_sys_bind+0x76/0x80 net/socket.c:1820 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6a67d9e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcce950828 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00007f6a68025fa0 RCX: 00007f6a67d9e0d9 RDX: 000000000000000c RSI: 0000200000000300 RDI: 0000000000000004 RBP: 00007f6a67e35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6a68025fac R14: 00007f6a68025fa0 R15: 00007f6a68025fa0 ================================================================================