forked from Minki/linux
f4eaed28c7
We currently trigger multiple memory leaks when replacing bpf
actions, besides others:
comm "tc", pid 1909, jiffies 4294851310 (age 1602.796s)
hex dump (first 32 bytes):
01 00 00 00 03 00 00 00 00 00 00 00 00 00 00 00 ................
18 b0 98 6d 00 88 ff ff 00 00 00 00 00 00 00 00 ...m............
backtrace:
[<ffffffff817e623e>] kmemleak_alloc+0x4e/0xb0
[<ffffffff8120a22d>] __vmalloc_node_range+0x1bd/0x2c0
[<ffffffff8120a37a>] __vmalloc+0x4a/0x50
[<ffffffff811a8d0a>] bpf_prog_alloc+0x3a/0xa0
[<ffffffff816c0684>] bpf_prog_create+0x44/0xa0
[<ffffffffa09ba4eb>] tcf_bpf_init+0x28b/0x3c0 [act_bpf]
[<ffffffff816d7001>] tcf_action_init_1+0x191/0x1b0
[<ffffffff816d70a2>] tcf_action_init+0x82/0xf0
[<ffffffff816d4d12>] tcf_exts_validate+0xb2/0xc0
[<ffffffffa09b5838>] cls_bpf_modify_existing+0x98/0x340 [cls_bpf]
[<ffffffffa09b5cd6>] cls_bpf_change+0x1a6/0x274 [cls_bpf]
[<ffffffff816d56e5>] tc_ctl_tfilter+0x335/0x910
[<ffffffff816b9145>] rtnetlink_rcv_msg+0x95/0x240
[<ffffffff816df34f>] netlink_rcv_skb+0xaf/0xc0
[<ffffffff816b909e>] rtnetlink_rcv+0x2e/0x40
[<ffffffff816deaaf>] netlink_unicast+0xef/0x1b0
Issue is that the old content from tcf_bpf is allocated and needs
to be released when we replace it. We seem to do that since the
beginning of act_bpf on the filter and insns, later on the name as
well.
Example test case, after patch:
# FOO="1,6 0 0 4294967295,"
# BAR="1,6 0 0 4294967294,"
# tc actions add action bpf bytecode "$FOO" index 2
# tc actions show action bpf
action order 0: bpf bytecode '1,6 0 0 4294967295' default-action pipe
index 2 ref 1 bind 0
# tc actions replace action bpf bytecode "$BAR" index 2
# tc actions show action bpf
action order 0: bpf bytecode '1,6 0 0 4294967294' default-action pipe
index 2 ref 1 bind 0
# tc actions replace action bpf bytecode "$FOO" index 2
# tc actions show action bpf
action order 0: bpf bytecode '1,6 0 0 4294967295' default-action pipe
index 2 ref 1 bind 0
# tc actions del action bpf index 2
[...]
# echo "scan" > /sys/kernel/debug/kmemleak
# cat /sys/kernel/debug/kmemleak | grep "comm \"tc\"" | wc -l
0
Fixes:
|
||
|---|---|---|
| .. | ||
| 6lowpan | ||
| 9p | ||
| 802 | ||
| 8021q | ||
| appletalk | ||
| atm | ||
| ax25 | ||
| batman-adv | ||
| bluetooth | ||
| bridge | ||
| caif | ||
| can | ||
| ceph | ||
| core | ||
| dcb | ||
| dccp | ||
| decnet | ||
| dns_resolver | ||
| dsa | ||
| ethernet | ||
| hsr | ||
| ieee802154 | ||
| ipv4 | ||
| ipv6 | ||
| ipx | ||
| irda | ||
| iucv | ||
| key | ||
| l2tp | ||
| lapb | ||
| llc | ||
| mac80211 | ||
| mac802154 | ||
| mpls | ||
| netfilter | ||
| netlabel | ||
| netlink | ||
| netrom | ||
| nfc | ||
| openvswitch | ||
| packet | ||
| phonet | ||
| rds | ||
| rfkill | ||
| rose | ||
| rxrpc | ||
| sched | ||
| sctp | ||
| sunrpc | ||
| switchdev | ||
| tipc | ||
| unix | ||
| vmw_vsock | ||
| wimax | ||
| wireless | ||
| x25 | ||
| xfrm | ||
| compat.c | ||
| Kconfig | ||
| Makefile | ||
| socket.c | ||
| sysctl_net.c | ||