kernel.git/net/sched/sch_api.c, branch linux-4.9.y

net: sched: avoid duplicates in classes dump

2021-03-17T15:10:14Z

commit bfc2560563586372212b0a8aeca7428975fa91fe upstream. This is a follow up of commit ea3274695353 ("net: sched: avoid duplicates in qdisc dump") which has fixed the issue only for the qdisc dump. The duplicate printing also occurs when dumping the classes via tc class show dev eth0 Fixes: 59cc1f61f09c ("net: sched: convert qdisc linked list to hashtable") Signed-off-by: Maximilian Heyne Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net_sched: reject silly cell_log in qdisc_get_rtab()

2021-02-10T08:09:23Z

commit e4bedf48aaa5552bc1f49703abd17606e7e6e82a upstream iproute2 probably never goes beyond 8 for the cell exponent, but stick to the max shift exponent for signed 32bit. UBSAN reported: UBSAN: shift-out-of-bounds in net/sched/sch_api.c:389:22 shift exponent 130 is too large for 32-bit type 'int' CPU: 1 PID: 8450 Comm: syz-executor586 Not tainted 5.11.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x183/0x22e lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] __ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395 __detect_linklayer+0x2a9/0x330 net/sched/sch_api.c:389 qdisc_get_rtab+0x2b5/0x410 net/sched/sch_api.c:435 cbq_init+0x28f/0x12c0 net/sched/sch_cbq.c:1180 qdisc_create+0x801/0x1470 net/sched/sch_api.c:1246 tc_modify_qdisc+0x9e3/0x1fc0 net/sched/sch_api.c:1662 rtnetlink_rcv_msg+0xb1d/0xe60 net/core/rtnetlink.c:5564 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x5a2/0x900 net/socket.c:2345 ___sys_sendmsg net/socket.c:2399 [inline] __sys_sendmsg+0x319/0x400 net/socket.c:2432 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Acked-by: Cong Wang Link: https://lore.kernel.org/r/20210114160637.1660597-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski [sudip: adjust context] Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

net_sched: refetch skb protocol for each filter

2019-01-31T07:12:33Z

[ Upstream commit cd0c4e70fc0ccfa705cdf55efb27519ce9337a26 ] Martin reported a set of filters don't work after changing from reclassify to continue. Looking into the code, it looks like skb protocol is not always fetched for each iteration of the filters. But, as demonstrated by Martin, TC actions could modify skb->protocol, for example act_vlan, this means we have to refetch skb protocol in each iteration, rather than using the one we fetch in the beginning of the loop. This bug is _not_ introduced by commit 3b3ae880266d ("net: sched: consolidate tc_classify{,_compat}"), technically, if act_vlan is the only action that modifies skb protocol, then it is commit c7e2b9689ef8 ("sched: introduce vlan action") which introduced this bug. Reported-by: Martin Olsson Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net_sched: avoid matching qdisc with zero handle

2017-11-18T10:22:23Z

[ Upstream commit 50317fce2cc70a2bbbc4b42c31bbad510382a53c ] Davide found the following script triggers a NULL pointer dereference: ip l a name eth0 type dummy tc q a dev eth0 parent :1 handle 1: htb This is because for a freshly created netdevice noop_qdisc is attached and when passing 'parent :1', kernel actually tries to match the major handle which is 0 and noop_qdisc has handle 0 so is matched by mistake. Commit 69012ae425d7 tries to fix a similar bug but still misses this case. Handle 0 is not a valid one, should be just skipped. In fact, kernel uses it as TC_H_UNSPEC. Fixes: 69012ae425d7 ("net: sched: fix handling of singleton qdiscs with qdisc_hash") Fixes: 59cc1f61f09c ("net: sched:convert qdisc linked list to hashtable") Reported-by: Davide Caratti Cc: Jiri Kosina Cc: Eric Dumazet Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net_sched: remove warning from qdisc_hash_add

2017-08-30T08:21:39Z

[ Upstream commit c90e95147c27b1780e76c6e8fea1b5c78d7d387f ] It was added in commit e57a784d8cae ("pkt_sched: set root qdisc before change() in attach_default_qdiscs()") to hide duplicates from "tc qdisc show" for incative deivices. After 59cc1f61f ("net: sched: convert qdisc linked list to hashtable") it triggered when classful qdisc is added to inactive device because default qdiscs are added before switching root qdisc. Anyway after commit ea3274695353 ("net: sched: avoid duplicates in qdisc dump") duplicates are filtered right in dumper. Signed-off-by: Konstantin Khlebnikov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: sched: Fix one possible panic when no destroy callback

2017-07-21T05:42:17Z

commit c1a4872ebfb83b1af7144f7b29ac8c4b344a12a8 upstream. When qdisc fail to init, qdisc_create would invoke the destroy callback to cleanup. But there is no check if the callback exists really. So it would cause the panic if there is no real destroy callback like the qdisc codel, fq, and so on. Take codel as an example following: When a malicious user constructs one invalid netlink msg, it would cause codel_init->codel_change->nla_parse_nested failed. Then kernel would invoke the destroy callback directly but qdisc codel doesn't define one. It causes one panic as a result. Now add one the check for destroy to avoid the possible panic. Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Signed-off-by: Gao Feng Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net_sched: fix error recovery at qdisc creation

2017-07-21T05:42:17Z

commit 87b60cfacf9f17cf71933c6e33b66e68160af71d upstream. Dmitry reported uses after free in qdisc code [1] The problem here is that ops->init() can return an error. qdisc_create_dflt() then call ops->destroy(), while qdisc_create() does _not_ call it. Four qdisc chose to call their own ops->destroy(), assuming their caller would not. This patch makes sure qdisc_create() calls ops->destroy() and fixes the four qdisc to avoid double free. [1] BUG: KASAN: use-after-free in mq_destroy+0x242/0x290 net/sched/sch_mq.c:33 at addr ffff8801d415d440 Read of size 8 by task syz-executor2/5030 CPU: 0 PID: 5030 Comm: syz-executor2 Not tainted 4.3.5-smp-DEV #119 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000046 ffff8801b435b870 ffffffff81bbbed4 ffff8801db000400 ffff8801d415d440 ffff8801d415dc40 ffff8801c4988510 ffff8801b435b898 ffffffff816682b1 ffff8801b435b928 ffff8801d415d440 ffff8801c49880c0 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0x6c/0x98 lib/dump_stack.c:51 [] kasan_object_err+0x21/0x70 mm/kasan/report.c:158 [] print_address_description mm/kasan/report.c:196 [inline] [] kasan_report_error+0x1b4/0x4b0 mm/kasan/report.c:285 [] kasan_report mm/kasan/report.c:305 [inline] [] __asan_report_load8_noabort+0x43/0x50 mm/kasan/report.c:326 [] mq_destroy+0x242/0x290 net/sched/sch_mq.c:33 [] qdisc_destroy+0x12d/0x290 net/sched/sch_generic.c:953 [] qdisc_create_dflt+0xf0/0x120 net/sched/sch_generic.c:848 [] attach_default_qdiscs net/sched/sch_generic.c:1029 [inline] [] dev_activate+0x6ad/0x880 net/sched/sch_generic.c:1064 [] __dev_open+0x221/0x320 net/core/dev.c:1403 [] __dev_change_flags+0x15e/0x3e0 net/core/dev.c:6858 [] dev_change_flags+0x8e/0x140 net/core/dev.c:6926 [] dev_ifsioc+0x446/0x890 net/core/dev_ioctl.c:260 [] dev_ioctl+0x1ba/0xb80 net/core/dev_ioctl.c:546 [] sock_do_ioctl+0x99/0xb0 net/socket.c:879 [] sock_ioctl+0x2a0/0x390 net/socket.c:958 [] vfs_ioctl fs/ioctl.c:44 [inline] [] do_vfs_ioctl+0x8a8/0xe50 fs/ioctl.c:611 [] SYSC_ioctl fs/ioctl.c:626 [inline] [] SyS_ioctl+0x94/0xc0 fs/ioctl.c:617 [] entry_SYSCALL_64_fastpath+0x12/0x17 Signed-off-by: Eric Dumazet Reported-by: Dmitry Vyukov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net sched: stylistic cleanups

2016-09-20T02:04:14Z

Signed-off-by: Jamal Hadi Salim Signed-off-by: David S. Miller

net: sched: avoid duplicates in qdisc dump

2016-08-19T04:19:08Z

tc_dump_qdisc() performs dumping of the per-device qdiscs in two phases; first, the "standard" dev->qdisc is being dumped. Second, if there is/are ingress queue(s), they are being dumped as well. After conversion of netdevice's qdisc linked-list into hashtable, these two sets are not in two disjunctive sets/lists any more, but are both "reachable" directly from netdevice's hashtable. As a consequence, the "full-depth" dump of the ingress qdiscs results in immediately hitting the netdevice hashtable again, and duplicating the dump that has already been performed for dev->qdisc. What in fact needs to be dumped in case of ingress queue is "just" the top-level ingress qdisc, as everything else has been dumped already. Fix this by extending tc_dump_qdisc_root() in a way that it can be instructed whether it should (while performing the "full" per-netdev qdisc dump) perform the whole recursion, or just dump "additional" top-level (ingress) qdiscs without performing any kind of recursion. This fixes duplicate dumps such as qdisc mq 0: root qdisc pfifo_fast 0: parent :4 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 qdisc pfifo_fast 0: parent :3 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 qdisc pfifo_fast 0: parent :2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 qdisc pfifo_fast 0: parent :1 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 qdisc clsact ffff: parent ffff:fff1 qdisc pfifo_fast 0: parent :4 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 qdisc pfifo_fast 0: parent :3 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 qdisc pfifo_fast 0: parent :2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 qdisc pfifo_fast 0: parent :1 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 Fixes: 59cc1f61f ("net: sched: convert qdisc linked list to hashtable") Reported-by: Daniel Borkmann Tested-by: Daniel Borkmann Signed-off-by: Jiri Kosina Signed-off-by: David S. Miller

net: sched: fix handling of singleton qdiscs with qdisc_hash

2016-08-19T04:19:08Z

qdisc_match_from_root() is now iterating over per-netdevice qdisc hashtable instead of going through a linked-list of qdiscs (independently on the actual underlying netdev), which was the case before the switch to hashtable for qdiscs. For singleton qdiscs, there is no underlying netdev associated though, and therefore dumping a singleton qdisc will panic, as qdisc_dev(root) will always be NULL. BUG: unable to handle kernel NULL pointer dereference at 0000000000000410 IP: [] qdisc_match_from_root+0x2c/0x70 PGD 1aceba067 PUD 1aceb7067 PMD 0 Oops: 0000 [#1] PREEMPT SMP [ ... ] task: ffff8801ec996e00 task.stack: ffff8801ec934000 RIP: 0010:[] [] qdisc_match_from_root+0x2c/0x70 RSP: 0018:ffff8801ec937ab0 EFLAGS: 00010203 RAX: 0000000000000408 RBX: ffff88025e612000 RCX: ffffffffffffffd8 RDX: 0000000000000000 RSI: 00000000ffff0000 RDI: ffffffff81cf8100 RBP: ffff8801ec937ab0 R08: 000000000001c160 R09: ffff8802668032c0 R10: ffffffff81cf8100 R11: 0000000000000030 R12: 00000000ffff0000 R13: ffff88025e612000 R14: ffffffff81cf3140 R15: 0000000000000000 FS: 00007f24b9af6740(0000) GS:ffff88026f280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000410 CR3: 00000001aceec000 CR4: 00000000001406e0 Stack: ffff8801ec937ad0 ffffffff81681210 ffff88025dd51a00 00000000fffffff1 ffff8801ec937b88 ffffffff81681e4e ffffffff81c42bc0 ffff880262431500 ffffffff81cf3140 ffff88025dd51a10 ffff88025dd51a24 00000000ec937b38 Call Trace: [] qdisc_lookup+0x40/0x50 [] tc_modify_qdisc+0x21e/0x550 [] rtnetlink_rcv_msg+0x95/0x220 [] ? __kmalloc_track_caller+0x172/0x230 [] ? rtnl_newlink+0x870/0x870 [] netlink_rcv_skb+0xa7/0xc0 [] rtnetlink_rcv+0x28/0x30 [] netlink_unicast+0x15b/0x210 [] netlink_sendmsg+0x319/0x390 [] sock_sendmsg+0x38/0x50 [] ___sys_sendmsg+0x256/0x260 [] ? __pagevec_lru_add_fn+0x135/0x280 [] ? pagevec_lru_move_fn+0xd0/0xf0 [] ? trace_event_raw_event_mm_lru_insertion+0x180/0x180 [] ? __lru_cache_add+0x75/0xb0 [] ? _raw_spin_unlock+0x16/0x40 [] ? handle_mm_fault+0x39f/0x1160 [] __sys_sendmsg+0x45/0x80 [] SyS_sendmsg+0x12/0x20 [] do_syscall_64+0x57/0xb0 Fix this by special-casing singleton qdiscs (those that don't have underlying netdevice) and introduce immediate handling of those rather than trying to go over an underlying netdevice. We're in the same situation in tc_dump_qdisc_root() and tc_dump_tclass_root(). Ultimately, this will have to be slightly reworked so that we are actually able to show singleton qdiscs (noop) in the dump properly; but we're not currently doing that anyway, so no regression there, and better do this in a gradual manner. Fixes: 59cc1f61f ("net: sched: convert qdisc linked list to hashtable") Reported-by: Daniel Borkmann Tested-by: Daniel Borkmann Reported-by: David Ahern Tested-by: David Ahern Signed-off-by: Jiri Kosina Signed-off-by: David S. Miller