From f1c88f5d2b2429121714f01d7ff47dee5f352649 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 27 Feb 2023 15:30:24 +0000 Subject: [PATCH] ila: do not generate empty messages in ila_xlat_nl_cmd_get_mapping() [ Upstream commit 693aa2c0d9b6d5b1f2745d31b6e70d09dbbaf06e ] ila_xlat_nl_cmd_get_mapping() generates an empty skb, triggerring a recent sanity check [1]. Instead, return an error code, so that user space can get it. [1] skb_assert_len WARNING: CPU: 0 PID: 5923 at include/linux/skbuff.h:2527 skb_assert_len include/linux/skbuff.h:2527 [inline] WARNING: CPU: 0 PID: 5923 at include/linux/skbuff.h:2527 __dev_queue_xmit+0x1bc0/0x3488 net/core/dev.c:4156 Modules linked in: CPU: 0 PID: 5923 Comm: syz-executor269 Not tainted 6.2.0-syzkaller-18300-g2ebd1fbb946d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skb_assert_len include/linux/skbuff.h:2527 [inline] pc : __dev_queue_xmit+0x1bc0/0x3488 net/core/dev.c:4156 lr : skb_assert_len include/linux/skbuff.h:2527 [inline] lr : __dev_queue_xmit+0x1bc0/0x3488 net/core/dev.c:4156 sp : ffff80001e0d6c40 x29: ffff80001e0d6e60 x28: dfff800000000000 x27: ffff0000c86328c0 x26: dfff800000000000 x25: ffff0000c8632990 x24: ffff0000c8632a00 x23: 0000000000000000 x22: 1fffe000190c6542 x21: ffff0000c8632a10 x20: ffff0000c8632a00 x19: ffff80001856e000 x18: ffff80001e0d5fc0 x17: 0000000000000000 x16: ffff80001235d16c x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000001 x11: ff80800008353a30 x10: 0000000000000000 x9 : 21567eaf25bfb600 x8 : 21567eaf25bfb600 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff80001e0d6558 x4 : ffff800015c74760 x3 : ffff800008596744 x2 : 0000000000000001 x1 : 0000000100000000 x0 : 000000000000000e Call trace: skb_assert_len include/linux/skbuff.h:2527 [inline] __dev_queue_xmit+0x1bc0/0x3488 net/core/dev.c:4156 dev_queue_xmit include/linux/netdevice.h:3033 [inline] __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline] __netlink_deliver_tap+0x45c/0x6f8 net/netlink/af_netlink.c:325 netlink_deliver_tap+0xf4/0x174 net/netlink/af_netlink.c:338 __netlink_sendskb net/netlink/af_netlink.c:1283 [inline] netlink_sendskb+0x6c/0x154 net/netlink/af_netlink.c:1292 netlink_unicast+0x334/0x8d4 net/netlink/af_netlink.c:1380 nlmsg_unicast include/net/netlink.h:1099 [inline] genlmsg_unicast include/net/genetlink.h:433 [inline] genlmsg_reply include/net/genetlink.h:443 [inline] ila_xlat_nl_cmd_get_mapping+0x620/0x7d0 net/ipv6/ila/ila_xlat.c:493 genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline] genl_rcv_msg+0x938/0xc1c net/netlink/genetlink.c:1065 netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2574 genl_rcv+0x38/0x50 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x800/0xae0 net/netlink/af_netlink.c:1942 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x558/0x844 net/socket.c:2479 ___sys_sendmsg net/socket.c:2533 [inline] __sys_sendmsg+0x26c/0x33c net/socket.c:2562 __do_sys_sendmsg net/socket.c:2571 [inline] __se_sys_sendmsg net/socket.c:2569 [inline] __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2569 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 irq event stamp: 136484 hardirqs last enabled at (136483): [] __up_console_sem+0x60/0xb4 kernel/printk/printk.c:345 hardirqs last disabled at (136484): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (136418): [] softirq_handle_end kernel/softirq.c:414 [inline] softirqs last enabled at (136418): [] __do_softirq+0xd4c/0xfa4 kernel/softirq.c:600 softirqs last disabled at (136371): [] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 ---[ end trace 0000000000000000 ]--- skb len=0 headroom=0 headlen=0 tailroom=192 mac=(0,0) net=(0,-1) trans=-1 shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0)) csum(0x0 ip_summed=0 complete_sw=0 valid=0 level=0) hash(0x0 sw=0 l4=0) proto=0x0010 pkttype=6 iif=0 dev name=nlmon0 feat=0x0000000000005861 Fixes: 688bdaed3ad7 ("ila: Add generic ILA translation facility") Reported-by: syzbot Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv6/ila/ila_xlat.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c index 5fc1f4e0c0cf0..10f1367eb4ca0 100644 --- a/net/ipv6/ila/ila_xlat.c +++ b/net/ipv6/ila/ila_xlat.c @@ -477,6 +477,7 @@ int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info) rcu_read_lock(); + ret = -ESRCH; ila = ila_lookup_by_params(&xp, ilan); if (ila) { ret = ila_dump_info(ila, -- 2.39.5