kernel.git/net/sched/act_api.c, branch linux-5.3.y

net: avoid potential infinite loop in tc_ctl_action()

2019-10-29T08:21:52Z

[ Upstream commit 39f13ea2f61b439ebe0060393e9c39925c9ee28c ] tc_ctl_action() has the ability to loop forever if tcf_action_add() returns -EAGAIN. This special case has been done in case a module needed to be loaded, but it turns out that tcf_add_notify() could also return -EAGAIN if the socket sk_rcvbuf limit is hit. We need to separate the two cases, and only loop for the module loading case. While we are at it, add a limit of 10 attempts since unbounded loops are always scary. syzbot repro was something like : socket(PF_NETLINK, SOCK_RAW|SOCK_NONBLOCK, NETLINK_ROUTE) = 3 write(3, ..., 38) = 38 setsockopt(3, SOL_SOCKET, SO_RCVBUF, [0], 4) = 0 sendmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{..., 388}], msg_controllen=0, msg_flags=0x10}, ...) NMI backtrace for cpu 0 CPU: 0 PID: 1054 Comm: khungtaskd Not tainted 5.4.0-rc1+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x9d0/0xef0 kernel/hung_task.c:289 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8859 Comm: syz-executor910 Not tainted 5.4.0-rc1+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:751 [inline] RIP: 0010:lockdep_hardirqs_off+0x1df/0x2e0 kernel/locking/lockdep.c:3453 Code: 5c 08 00 00 5b 41 5c 41 5d 5d c3 48 c7 c0 58 1d f3 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 d3 00 00 00 <48> 83 3d 21 9e 99 07 00 0f 84 b9 00 00 00 9c 58 0f 1f 44 00 00 f6 RSP: 0018:ffff8880a6f3f1b8 EFLAGS: 00000046 RAX: 1ffffffff11e63ab RBX: ffff88808c9c6080 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff88808c9c6914 RBP: ffff8880a6f3f1d0 R08: ffff88808c9c6080 R09: fffffbfff16be5d1 R10: fffffbfff16be5d0 R11: 0000000000000003 R12: ffffffff8746591f R13: ffff88808c9c6080 R14: ffffffff8746591f R15: 0000000000000003 FS: 00000000011e4880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000a8920000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_off+0x62/0x240 kernel/trace/trace_preemptirq.c:45 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] _raw_spin_lock_irqsave+0x6f/0xcd kernel/locking/spinlock.c:159 __wake_up_common_lock+0xc8/0x150 kernel/sched/wait.c:122 __wake_up+0xe/0x10 kernel/sched/wait.c:142 netlink_unlock_table net/netlink/af_netlink.c:466 [inline] netlink_unlock_table net/netlink/af_netlink.c:463 [inline] netlink_broadcast_filtered+0x705/0xb80 net/netlink/af_netlink.c:1514 netlink_broadcast+0x3a/0x50 net/netlink/af_netlink.c:1534 rtnetlink_send+0xdd/0x110 net/core/rtnetlink.c:714 tcf_add_notify net/sched/act_api.c:1343 [inline] tcf_action_add+0x243/0x370 net/sched/act_api.c:1362 tc_ctl_action+0x3b5/0x4bc net/sched/act_api.c:1410 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5386 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5404 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:657 ___sys_sendmsg+0x803/0x920 net/socket.c:2311 __sys_sendmsg+0x105/0x1d0 net/socket.c:2356 __do_sys_sendmsg net/socket.c:2365 [inline] __se_sys_sendmsg net/socket.c:2363 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x440939 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot+cf0adbb9c28c8866c788@syzkaller.appspotmail.com Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net_sched: fix backward compatibility for TCA_ACT_KIND

2019-10-29T08:21:49Z

[ Upstream commit 4b793feccae3b06764268377a4030eb774ed924e ] For TCA_ACT_KIND, we have to keep the backward compatibility too, and rely on nla_strlcpy() to check and terminate the string with a NUL. Note for TC actions, nla_strcmp() is already used to compare kind strings, so we don't need to fix other places. Fixes: 199ce850ce11 ("net_sched: add policy validation for action attributes") Reported-by: Marcelo Ricardo Leitner Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Reviewed-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net_sched: add policy validation for action attributes

2019-10-05T13:11:21Z

[ Upstream commit 199ce850ce112315cfc68d42b694bcaa27b097b7 ] Similar to commit 8b4c3cdd9dd8 ("net: sched: Add policy validation for tc attributes"), we need to add proper policy validation for TC action attributes too. Cc: David Ahern Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Acked-by: Jiri Pirko Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

idr: fix overflow case for idr_for_each_entry_ul()

2019-07-02T02:15:46Z

idr_for_each_entry_ul() is buggy as it can't handle overflow case correctly. When we have an ID == UINT_MAX, it becomes an infinite loop. This happens when running on 32-bit CPU where unsigned long has the same size with unsigned int. There is no better way to fix this than casting it to a larger integer, but we can't just 64 bit integer on 32 bit CPU. Instead we could just use an additional integer to help us to detect this overflow case, that is, adding a new parameter to this macro. Fortunately tc action is its only user right now. Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use IDR") Reported-by: Li Shuang Tested-by: Davide Caratti Cc: Matthew Wilcox Cc: Chris Mi Signed-off-by: Cong Wang Signed-off-by: David S. Miller

Merge tag 'spdx-5.2-rc3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2019-05-31T15:34:32Z

Pull yet more SPDX updates from Greg KH: "Here is another set of reviewed patches that adds SPDX tags to different kernel files, based on a set of rules that are being used to parse the comments to try to determine that the license of the file is "GPL-2.0-or-later" or "GPL-2.0-only". Only the "obvious" versions of these matches are included here, a number of "non-obvious" variants of text have been found but those have been postponed for later review and analysis. There is also a patch in here to add the proper SPDX header to a bunch of Kbuild files that we have missed in the past due to new files being added and forgetting that Kbuild uses two different file names for Makefiles. This issue was reported by the Kbuild maintainer. These patches have been out for review on the linux-spdx@vger mailing list, and while they were created by automatic tools, they were hand-verified by a bunch of different people, all whom names are on the patches are reviewers" * tag 'spdx-5.2-rc3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (82 commits) treewide: Add SPDX license identifier - Kbuild treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 225 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 224 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 223 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 222 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 221 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 220 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 218 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 217 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 216 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 215 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 214 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 213 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 211 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 210 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 209 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 207 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 203 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 ...

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

2019-05-30T18:26:32Z

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

net: sched: don't use tc_action->order during action dump

2019-05-24T20:27:52Z

Function tcf_action_dump() relies on tc_action->order field when starting nested nla to send action data to userspace. This approach breaks in several cases: - When multiple filters point to same shared action, tc_action->order field is overwritten each time it is attached to filter. This causes filter dump to output action with incorrect attribute for all filters that have the action in different position (different order) from the last set tc_action->order value. - When action data is displayed using tc action API (RTM_GETACTION), action order is overwritten by tca_action_gd() according to its position in resulting array of nl attributes, which will break filter dump for all filters attached to that shared action that expect it to have different order value. Don't rely on tc_action->order when dumping actions. Set nla according to action position in resulting array of actions instead. Signed-off-by: Vlad Buslov Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller

netlink: make validation more configurable for future strictness

2019-04-27T21:07:21Z

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

2019-04-27T21:03:44Z

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: let actions use RCU to access 'goto_chain'

2019-03-21T20:26:42Z

use RCU when accessing the action chain, to avoid use after free in the traffic path when 'goto chain' is replaced on existing TC actions (see script below). Since the control action is read in the traffic path without holding the action spinlock, we need to explicitly ensure that a->goto_chain is not NULL before dereferencing (i.e it's not sufficient to rely on the value of TC_ACT_GOTO_CHAIN bits). Not doing so caused NULL dereferences in tcf_action_goto_chain_exec() when the following script: # tc chain add dev dd0 chain 42 ingress protocol ip flower \ > ip_proto udp action pass index 4 # tc filter add dev dd0 ingress protocol ip flower \ > ip_proto udp action csum udp goto chain 42 index 66 # tc chain del dev dd0 chain 42 ingress (start UDP traffic towards dd0) # tc action replace action csum udp pass index 66 was run repeatedly for several hours. Suggested-by: Cong Wang Suggested-by: Vlad Buslov Signed-off-by: Davide Caratti Signed-off-by: David S. Miller