On Thu, Jan 14, 2021 at 8:06 AM Eric Dumazet <eric.duma...@gmail.com> wrote:
>
> From: Eric Dumazet <eduma...@google.com>
>
> iproute2 probably never goes beyond 8 for the cell exponent,
> but stick to the max shift exponent for signed 32bit.
>
> UBSAN reported:
> UBSAN: shift-out-of-bounds in net/sched/sch_api.c:389:22
> shift exponent 130 is too large for 32-bit type 'int'
> CPU: 1 PID: 8450 Comm: syz-executor586 Not tainted 5.11.0-rc3-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+0x183/0x22e lib/dump_stack.c:120
> ubsan_epilogue lib/ubsan.c:148 [inline]
> __ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395
> __detect_linklayer+0x2a9/0x330 net/sched/sch_api.c:389
> qdisc_get_rtab+0x2b5/0x410 net/sched/sch_api.c:435
> cbq_init+0x28f/0x12c0 net/sched/sch_cbq.c:1180
> qdisc_create+0x801/0x1470 net/sched/sch_api.c:1246
> tc_modify_qdisc+0x9e3/0x1fc0 net/sched/sch_api.c:1662
> rtnetlink_rcv_msg+0xb1d/0xe60 net/core/rtnetlink.c:5564
> netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2494
> netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
> netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1330
> netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1919
> sock_sendmsg_nosec net/socket.c:652 [inline]
> sock_sendmsg net/socket.c:672 [inline]
> ____sys_sendmsg+0x5a2/0x900 net/socket.c:2345
> ___sys_sendmsg net/socket.c:2399 [inline]
> __sys_sendmsg+0x319/0x400 net/socket.c:2432
> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Reported-by: syzbot <syzkal...@googlegroups.com>
Acked-by: Cong Wang <cong.w...@bytedance.com>
Thanks.
