Re: [syzbot] UBSAN: shift-out-of-bounds in nl802154_new_interface

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
UBSAN: shift-out-of-bounds in nl802154_new_interface

================================================================================
UBSAN: shift-out-of-bounds in net/ieee802154/nl802154.c:914:44
shift exponent -1627389953 is negative
CPU: 1 PID: 10118 Comm: syz-executor.5 Not tainted 5.11.0-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+0xfa/0x151 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
nl802154_new_interface.cold+0x19/0x1e net/ieee802154/nl802154.c:914
genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:739
genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:800
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
sock_sendmsg_nosec net/socket.c:654 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:674
____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
___sys_sendmsg+0xf3/0x170 net/socket.c:2404
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2437
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x466019
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9539e12188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466019
RDX: 0000000000000000 RSI: 0000000020000ac0 RDI: 0000000000000004
RBP: 00000000004bd067 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffd4faa5aef R14: 00007f9539e12300 R15: 0000000000022000
================================================================================


Tested on:

commit: 9270bbe2 Merge git://git.kernel.org/pub/scm/linux/kernel/g..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=113920ecd00000
kernel config: https://syzkaller.appspot.com/x/.config?x=57530b761c47820d
dashboard link: https://syzkaller.appspot.com/bug?extid=7bf7b22759195c9a21e9
compiler: