lwn.git/net/sched/sch_tbf.c, branch v5.2-rc7

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

netlink: make validation more configurable for future strictness

2019-04-27T21:07:21+00:00

We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

netlink: make nla_nest_start() add NLA_F_NESTED flag

2019-04-27T21:03:44+00:00

Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek Acked-by: Jiri Pirko Acked-by: David Ahern Signed-off-by: David S. Miller

net: sched: introduce and use qdisc tree flush/purge helpers

2019-04-01T21:50:13+00:00

The same code to flush qdisc tree and purge the qdisc queue is duplicated in many places and in most cases it does not respect NOLOCK qdisc: the global backlog len is used and the per CPU values are ignored. This change addresses the above, factoring-out the relevant code and using the helpers introduced by the previous patch to fetch the correct backlog len. Fixes: c5ad119fb6c0 ("net: sched: pfifo_fast use skb_array") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

sched: Avoid dereferencing skb pointer after child enqueue

2019-01-16T04:12:00+00:00

Parent qdiscs may dereference the pointer to the enqueued skb after enqueue. However, both CAKE and TBF call consume_skb() on the original skb when splitting GSO packets, leading to a potential use-after-free in the parent. Fix this by avoiding dereferencing the skb pointer after enqueueing to the child. Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller

net: sched: rename qdisc_destroy() to qdisc_put()

2018-09-26T03:17:35+00:00

Current implementation of qdisc_destroy() decrements Qdisc reference counter and only actually destroy Qdisc if reference counter value reached zero. Rename qdisc_destroy() to qdisc_put() in order for it to better describe the way in which this function currently implemented and used. Extract code that deallocates Qdisc into new private qdisc_destroy() function. It is intended to be shared between regular qdisc_put() and its unlocked version that is introduced in next patch in this series. Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller

net: Add and use skb_mark_not_on_list().

2018-09-10T17:06:54+00:00

An SKB is not on a list if skb->next is NULL. Codify this convention into a helper function and use it where we are dequeueing an SKB and need to mark it as such. Signed-off-by: David S. Miller

net: sched: red: avoid hashing NULL child

2018-05-18T17:52:32+00:00

Hangbin reported an Oops triggered by the syzkaller qdisc rules: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN PTI Modules linked in: sch_red CPU: 0 PID: 28699 Comm: syz-executor5 Not tainted 4.17.0-rc4.kcov #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:qdisc_hash_add+0x26/0xa0 RSP: 0018:ffff8800589cf470 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff824ad971 RDX: 0000000000000007 RSI: ffffc9000ce9f000 RDI: 000000000000003c RBP: 0000000000000001 R08: ffffed000b139ea2 R09: ffff8800589cf4f0 R10: ffff8800589cf50f R11: ffffed000b139ea2 R12: ffff880054019fc0 R13: ffff880054019fb4 R14: ffff88005c0af600 R15: ffff880054019fb0 FS: 00007fa6edcb1700(0000) GS:ffff88005ce00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000740 CR3: 000000000fc16000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: red_change+0x2d2/0xed0 [sch_red] qdisc_create+0x57e/0xef0 tc_modify_qdisc+0x47f/0x14e0 rtnetlink_rcv_msg+0x6a8/0x920 netlink_rcv_skb+0x2a2/0x3c0 netlink_unicast+0x511/0x740 netlink_sendmsg+0x825/0xc30 sock_sendmsg+0xc5/0x100 ___sys_sendmsg+0x778/0x8e0 __sys_sendmsg+0xf5/0x1b0 do_syscall_64+0xbd/0x3b0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x450869 RSP: 002b:00007fa6edcb0c48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa6edcb16b4 RCX: 0000000000450869 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000008778 R14: 0000000000702838 R15: 00007fa6edcb1700 Code: e9 0b fe ff ff 0f 1f 44 00 00 55 53 48 89 fb 89 f5 e8 3f 07 f3 fe 48 8d 7b 3c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 51 RIP: qdisc_hash_add+0x26/0xa0 RSP: ffff8800589cf470 When a red qdisc is updated with a 0 limit, the child qdisc is left unmodified, no additional scheduler is created in red_change(), the 'child' local variable is rightfully NULL and must not add it to the hash table. This change addresses the above issue moving qdisc_hash_add() right after the child qdisc creation. It additionally removes unneeded checks for noop_qdisc. Reported-by: Hangbin Liu Fixes: 49b499718fa1 ("net: sched: make default fifo qdiscs appear in the dump") Signed-off-by: Paolo Abeni Acked-by: Jiri Kosina Signed-off-by: David S. Miller

net: sched: tbf: handle GSO_BY_FRAGS case in enqueue

2018-03-04T22:49:17+00:00

tbf_enqueue() checks the size of a packet before enqueuing it. However, the GSO size check does not consider the GSO_BY_FRAGS case, and so will drop GSO SCTP packets, causing a massive drop in throughput. Use skb_gso_validate_mac_len() instead, as it does consider that case. Signed-off-by: Daniel Axtens Reviewed-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

net: create skb_gso_validate_mac_len()

2018-02-01T14:36:03+00:00

If you take a GSO skb, and split it into packets, will the MAC length (L2 + L3 + L4 headers + payload) of those packets be small enough to fit within a given length? Move skb_gso_mac_seglen() to skbuff.h with other related functions like skb_gso_network_seglen() so we can use it, and then create skb_gso_validate_mac_len to do the full calculation. Signed-off-by: Daniel Axtens Signed-off-by: David S. Miller