| From foo@baz Thu Feb 4 04:10:00 PM CET 2021 |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Thu, 14 Jan 2021 08:06:37 -0800 |
| Subject: net_sched: reject silly cell_log in qdisc_get_rtab() |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| commit e4bedf48aaa5552bc1f49703abd17606e7e6e82a upstream |
| |
| 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 <edumazet@google.com> |
| Reported-by: syzbot <syzkaller@googlegroups.com> |
| Acked-by: Cong Wang <cong.wang@bytedance.com> |
| Link: https://lore.kernel.org/r/20210114160637.1660597-1-eric.dumazet@gmail.com |
| Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
| [sudip: adjust context] |
| Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/sched/sch_api.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/net/sched/sch_api.c |
| +++ b/net/sched/sch_api.c |
| @@ -397,7 +397,8 @@ struct qdisc_rate_table *qdisc_get_rtab( |
| { |
| struct qdisc_rate_table *rtab; |
| |
| - if (tab == NULL || r->rate == 0 || r->cell_log == 0 || |
| + if (tab == NULL || r->rate == 0 || |
| + r->cell_log == 0 || r->cell_log >= 32 || |
| nla_len(tab) != TC_RTAB_SIZE) |
| return NULL; |
| |