From: Eric Dumazet edumazet@google.com
commit bcd0cf19ef8258ac31b9a20248b05c15a1f4b4b0 upstream.
tc_index being 16bit wide, we need to check that TCA_TCINDEX_SHIFT attribute is not silly.
UBSAN: shift-out-of-bounds in net/sched/cls_tcindex.c:260:29 shift exponent 255 is too large for 32-bit type 'int' CPU: 0 PID: 8516 Comm: syz-executor228 Not tainted 5.10.0-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+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 valid_perfect_hash net/sched/cls_tcindex.c:260 [inline] tcindex_set_parms.cold+0x1b/0x215 net/sched/cls_tcindex.c:425 tcindex_change+0x232/0x340 net/sched/cls_tcindex.c:546 tc_new_tfilter+0x13fb/0x21b0 net/sched/cls_api.c:2127 rtnetlink_rcv_msg+0x8b6/0xb80 net/core/rtnetlink.c:5555 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x907/0xe40 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2336 ___sys_sendmsg+0xf3/0x170 net/socket.c:2390 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2423 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 Link: https://lore.kernel.org/r/20210114185229.1742255-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/sched/cls_tcindex.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/net/sched/cls_tcindex.c +++ b/net/sched/cls_tcindex.c @@ -366,9 +366,13 @@ tcindex_set_parms(struct net *net, struc if (tb[TCA_TCINDEX_MASK]) cp->mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
- if (tb[TCA_TCINDEX_SHIFT]) + if (tb[TCA_TCINDEX_SHIFT]) { cp->shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]); - + if (cp->shift > 16) { + err = -EINVAL; + goto errout; + } + } if (!cp->hash) { /* Hash not specified, use perfect hash if the upper limit * of the hashing index is below the threshold.