[PATCH 4.18 013/197] net: sched: action_ife: take reference to meta module

From: Greg Kroah-Hartman
Date: Thu Sep 13 2018 - 09:50:35 EST

4.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vlad Buslov <vladbu@xxxxxxxxxxxx>

[ Upstream commit 84cb8eb26cb9ce3c79928094962a475a9d850a53 ]

Recent refactoring of add_metainfo() caused use_all_metadata() to add
metainfo to ife action metalist without taking reference to module. This
causes warning in module_put called from ife action cleanup function.

Implement add_metainfo_and_get_ops() function that returns with reference
to module taken if metainfo was added successfully, and call it from
use_all_metadata(), instead of calling __add_metainfo() directly.

Example warning:

[ 646.344393] WARNING: CPU: 1 PID: 2278 at kernel/module.c:1139 module_put+0x1cb/0x230
[ 646.352437] Modules linked in: act_meta_skbtcindex act_meta_mark act_meta_skbprio act_ife ife veth nfsv3 nfs fscache xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c tun ebtable_filter ebtables ip6table_filter ip6_tables bridge stp llc mlx5_ib ib_uverbs ib_core intel_rapl sb_edac x86_pkg_temp_thermal mlx5_core coretemp kvm_intel kvm nfsd igb irqbypass crct10dif_pclmul devlink crc32_pclmul mei_me joydev ses crc32c_intel enclosure auth_rpcgss i2c_algo_bit ioatdma ptp mei pps_core ghash_clmulni_intel iTCO_wdt iTCO_vendor_support pcspkr dca ipmi_ssif lpc_ich target_core_mod i2c_i801 ipmi_si ipmi_devintf pcc_cpufreq wmi ipmi_msghandler nfs_acl lockd acpi_pad acpi_power_meter grace sunrpc mpt3sas raid_class scsi_transport_sas
[ 646.425631] CPU: 1 PID: 2278 Comm: tc Not tainted 4.19.0-rc1+ #799
[ 646.432187] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
[ 646.440595] RIP: 0010:module_put+0x1cb/0x230
[ 646.445238] Code: f3 66 94 02 e8 26 ff fa ff 85 c0 74 11 0f b6 1d 51 30 94 02 80 fb 01 77 60 83 e3 01 74 13 65 ff 0d 3a 83 db 73 e9 2b ff ff ff <0f> 0b e9 00 ff ff ff e8 59 01 fb ff 85 c0 75 e4 48 c7 c2 20 62 6b
[ 646.464997] RSP: 0018:ffff880354d37068 EFLAGS: 00010286
[ 646.470599] RAX: 0000000000000000 RBX: ffffffffc0a52518 RCX: ffffffff8c2668db
[ 646.478118] RDX: 0000000000000003 RSI: dffffc0000000000 RDI: ffffffffc0a52518
[ 646.485641] RBP: ffffffffc0a52180 R08: fffffbfff814a4a4 R09: fffffbfff814a4a3
[ 646.493164] R10: ffffffffc0a5251b R11: fffffbfff814a4a4 R12: 1ffff1006a9a6e0d
[ 646.500687] R13: 00000000ffffffff R14: ffff880362bab890 R15: dead000000000100
[ 646.508213] FS: 00007f4164c99800(0000) GS:ffff88036fe40000(0000) knlGS:0000000000000000
[ 646.516961] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 646.523080] CR2: 00007f41638b8420 CR3: 0000000351df0004 CR4: 00000000001606e0
[ 646.530595] Call Trace:
[ 646.533408] ? find_symbol_in_section+0x260/0x260
[ 646.538509] tcf_ife_cleanup+0x11b/0x200 [act_ife]
[ 646.543695] tcf_action_cleanup+0x29/0xa0
[ 646.548078] __tcf_action_put+0x5a/0xb0
[ 646.552289] ? nla_put+0x65/0xe0
[ 646.555889] __tcf_idr_release+0x48/0x60
[ 646.560187] tcf_generic_walker+0x448/0x6b0
[ 646.564764] ? tcf_action_dump_1+0x450/0x450
[ 646.569411] ? __lock_is_held+0x84/0x110
[ 646.573720] ? tcf_ife_walker+0x10c/0x20f [act_ife]
[ 646.578982] tca_action_gd+0x972/0xc40
[ 646.583129] ? tca_get_fill.constprop.17+0x250/0x250
[ 646.588471] ? mark_lock+0xcf/0x980
[ 646.592324] ? check_chain_key+0x140/0x1f0
[ 646.596832] ? debug_show_all_locks+0x240/0x240
[ 646.601839] ? memset+0x1f/0x40
[ 646.605350] ? nla_parse+0xca/0x1a0
[ 646.609217] tc_ctl_action+0x215/0x230
[ 646.613339] ? tcf_action_add+0x220/0x220
[ 646.617748] rtnetlink_rcv_msg+0x56a/0x6d0
[ 646.622227] ? rtnl_fdb_del+0x3f0/0x3f0
[ 646.626466] netlink_rcv_skb+0x18d/0x200
[ 646.630752] ? rtnl_fdb_del+0x3f0/0x3f0
[ 646.634959] ? netlink_ack+0x500/0x500
[ 646.639106] netlink_unicast+0x2d0/0x370
[ 646.643409] ? netlink_attachskb+0x340/0x340
[ 646.648050] ? _copy_from_iter_full+0xe9/0x3e0
[ 646.652870] ? import_iovec+0x11e/0x1c0
[ 646.657083] netlink_sendmsg+0x3b9/0x6a0
[ 646.661388] ? netlink_unicast+0x370/0x370
[ 646.665877] ? netlink_unicast+0x370/0x370
[ 646.670351] sock_sendmsg+0x6b/0x80
[ 646.674212] ___sys_sendmsg+0x4a1/0x520
[ 646.678443] ? copy_msghdr_from_user+0x210/0x210
[ 646.683463] ? lock_downgrade+0x320/0x320
[ 646.687849] ? debug_show_all_locks+0x240/0x240
[ 646.692760] ? do_raw_spin_unlock+0xa2/0x130
[ 646.697418] ? _raw_spin_unlock+0x24/0x30
[ 646.701798] ? __handle_mm_fault+0x1819/0x1c10
[ 646.706619] ? __pmd_alloc+0x320/0x320
[ 646.710738] ? debug_show_all_locks+0x240/0x240
[ 646.715649] ? restore_nameidata+0x7b/0xa0
[ 646.720117] ? check_chain_key+0x140/0x1f0
[ 646.724590] ? check_chain_key+0x140/0x1f0
[ 646.729070] ? __fget_light+0xbc/0xd0
[ 646.733121] ? __sys_sendmsg+0xd7/0x150
[ 646.737329] __sys_sendmsg+0xd7/0x150
[ 646.741359] ? __ia32_sys_shutdown+0x30/0x30
[ 646.746003] ? up_read+0x53/0x90
[ 646.749601] ? __do_page_fault+0x484/0x780
[ 646.754105] ? do_syscall_64+0x1e/0x2c0
[ 646.758320] do_syscall_64+0x72/0x2c0
[ 646.762353] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 646.767776] RIP: 0033:0x7f4163872150
[ 646.771713] Code: 8b 15 3c 7d 2b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb cd 66 0f 1f 44 00 00 83 3d b9 d5 2b 00 00 75 10 b8 2e 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be cd 00 00 48 89 04 24
[ 646.791474] RSP: 002b:00007ffdef7d6b58 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 646.799721] RAX: ffffffffffffffda RBX: 0000000000000024 RCX: 00007f4163872150
[ 646.807240] RDX: 0000000000000000 RSI: 00007ffdef7d6bd0 RDI: 0000000000000003
[ 646.814760] RBP: 000000005b8b9482 R08: 0000000000000001 R09: 0000000000000000
[ 646.822286] R10: 00000000000005e7 R11: 0000000000000246 R12: 00007ffdef7dad20
[ 646.829807] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000679bc0
[ 646.837360] irq event stamp: 6083
[ 646.841043] hardirqs last enabled at (6081): [<ffffffff8c220a7d>] __call_rcu+0x17d/0x500
[ 646.849882] hardirqs last disabled at (6083): [<ffffffff8c004f06>] trace_hardirqs_off_thunk+0x1a/0x1c
[ 646.859775] softirqs last enabled at (5968): [<ffffffff8d4004a1>] __do_softirq+0x4a1/0x6ee
[ 646.868784] softirqs last disabled at (6082): [<ffffffffc0a78759>] tcf_ife_cleanup+0x39/0x200 [act_ife]
[ 646.878845] ---[ end trace b1b8c12ffe51e657 ]---

Fixes: 5ffe57da29b3 ("act_ife: fix a potential deadlock")
Signed-off-by: Vlad Buslov <vladbu@xxxxxxxxxxxx>
Acked-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/act_ife.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -324,6 +324,20 @@ static int __add_metainfo(const struct t
return ret;
}

+static int add_metainfo_and_get_ops(const struct tcf_meta_ops *ops,
+ struct tcf_ife_info *ife, u32 metaid,
+ bool exists)
+{
+ int ret;
+
+ if (!try_module_get(ops->owner))
+ return -ENOENT;
+ ret = __add_metainfo(ops, ife, metaid, NULL, 0, true, exists);
+ if (ret)
+ module_put(ops->owner);
+ return ret;
+}
+
static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
int len, bool exists)
{
@@ -347,7 +361,7 @@ static int use_all_metadata(struct tcf_i

read_lock(&ife_mod_lock);
list_for_each_entry(o, &ifeoplist, list) {
- rc = __add_metainfo(o, ife, o->metaid, NULL, 0, true, exists);
+ rc = add_metainfo_and_get_ops(o, ife, o->metaid, exists);
if (rc == 0)
installed += 1;
}