| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <df5ad08f-e91b-4501-00d9-c6cccf149f93@mojatatu.com>
Date: Wed, 26 Apr 2023 11:27:22 -0300
From: Pedro Tammela <pctammela@...atatu.com>
To: Vlad Buslov <vladbu@...dia.com>, davem@...emloft.net,
kuba@...nel.org
Cc: netdev@...r.kernel.org, jhs@...atatu.com, xiyou.wangcong@...il.com,
jiri@...nulli.us, marcelo.leitner@...il.com, paulb@...dia.com,
simon.horman@...igine.com
Subject: Re: [PATCH net 1/2] net/sched: flower: fix filter idr initialization
On 26/04/2023 09:14, Vlad Buslov wrote:
> The cited commit moved idr initialization too early in fl_change() which
> allows concurrent users to access the filter that is still being
> initialized and is in inconsistent state, which, in turn, can cause NULL
> pointer dereference [0]. Since there is no obvious way to fix the ordering
> without reverting the whole cited commit, alternative approach taken to
> first insert NULL pointer into idr in order to allocate the handle but
> still cause fl_get() to return NULL and prevent concurrent users from
> seeing the filter while providing miss-to-action infrastructure with valid
> handle id early in fl_change().
>
> [ 152.434728] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN
> [ 152.436163] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> [ 152.437269] CPU: 4 PID: 3877 Comm: tc Not tainted 6.3.0-rc4+ #5
> [ 152.438110] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
> [ 152.439644] RIP: 0010:fl_dump_key+0x8b/0x1d10 [cls_flower]
> [ 152.440461] Code: 01 f2 02 f2 c7 40 08 04 f2 04 f2 c7 40 0c 04 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 00 01 00 00 48 89 c8 48 c1 e8 03 <0f> b6 04 10 84 c0 74 08 3c 03 0f 8e 98 19 00 00 8b 13 85 d2 74 57
> [ 152.442885] RSP: 0018:ffff88817a28f158 EFLAGS: 00010246
> [ 152.443851] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> [ 152.444826] RDX: dffffc0000000000 RSI: ffffffff8500ae80 RDI: ffff88810a987900
> [ 152.445791] RBP: ffff888179d88240 R08: ffff888179d8845c R09: ffff888179d88240
> [ 152.446780] R10: ffffed102f451e48 R11: 00000000fffffff2 R12: ffff88810a987900
> [ 152.447741] R13: ffffffff8500ae80 R14: ffff88810a987900 R15: ffff888149b3c738
> [ 152.448756] FS: 00007f5eb2a34800(0000) GS:ffff88881ec00000(0000) knlGS:0000000000000000
> [ 152.449888] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 152.450685] CR2: 000000000046ad19 CR3: 000000010b0bd006 CR4: 0000000000370ea0
> [ 152.451641] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 152.452628] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [ 152.453588] Call Trace:
> [ 152.454032] <TASK>
> [ 152.454447] ? netlink_sendmsg+0x7a1/0xcb0
> [ 152.455109] ? sock_sendmsg+0xc5/0x190
> [ 152.455689] ? ____sys_sendmsg+0x535/0x6b0
> [ 152.456320] ? ___sys_sendmsg+0xeb/0x170
> [ 152.456916] ? do_syscall_64+0x3d/0x90
> [ 152.457529] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0
> [ 152.458321] ? ___sys_sendmsg+0xeb/0x170
> [ 152.458958] ? __sys_sendmsg+0xb5/0x140
> [ 152.459564] ? do_syscall_64+0x3d/0x90
> [ 152.460122] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0
> [ 152.460852] ? fl_dump_key_options.part.0+0xea0/0xea0 [cls_flower]
> [ 152.461710] ? _raw_spin_lock+0x7a/0xd0
> [ 152.462299] ? _raw_read_lock_irq+0x30/0x30
> [ 152.462924] ? nla_put+0x15e/0x1c0
> [ 152.463480] fl_dump+0x228/0x650 [cls_flower]
> [ 152.464112] ? fl_tmplt_dump+0x210/0x210 [cls_flower]
> [ 152.464854] ? __kmem_cache_alloc_node+0x1a7/0x330
> [ 152.465592] ? nla_put+0x15e/0x1c0
> [ 152.466160] tcf_fill_node+0x515/0x9a0
> [ 152.466766] ? tc_setup_offload_action+0xf0/0xf0
> [ 152.467463] ? __alloc_skb+0x13c/0x2a0
> [ 152.468067] ? __build_skb_around+0x330/0x330
> [ 152.468814] ? fl_get+0x107/0x1a0 [cls_flower]
> [ 152.469503] tc_del_tfilter+0x718/0x1330
> [ 152.470115] ? is_bpf_text_address+0xa/0x20
> [ 152.470765] ? tc_ctl_chain+0xee0/0xee0
> [ 152.471335] ? __kernel_text_address+0xe/0x30
> [ 152.471948] ? unwind_get_return_address+0x56/0xa0
> [ 152.472639] ? __thaw_task+0x150/0x150
> [ 152.473218] ? arch_stack_walk+0x98/0xf0
> [ 152.473839] ? __stack_depot_save+0x35/0x4c0
> [ 152.474501] ? stack_trace_save+0x91/0xc0
> [ 152.475119] ? security_capable+0x51/0x90
> [ 152.475741] rtnetlink_rcv_msg+0x2c1/0x9d0
> [ 152.476387] ? rtnl_calcit.isra.0+0x2b0/0x2b0
> [ 152.477042] ? __sys_sendmsg+0xb5/0x140
> [ 152.477664] ? do_syscall_64+0x3d/0x90
> [ 152.478255] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0
> [ 152.479010] ? __stack_depot_save+0x35/0x4c0
> [ 152.479679] ? __stack_depot_save+0x35/0x4c0
> [ 152.480346] netlink_rcv_skb+0x12c/0x360
> [ 152.480929] ? rtnl_calcit.isra.0+0x2b0/0x2b0
> [ 152.481517] ? do_syscall_64+0x3d/0x90
> [ 152.482061] ? netlink_ack+0x1550/0x1550
> [ 152.482612] ? rhashtable_walk_peek+0x170/0x170
> [ 152.483262] ? kmem_cache_alloc_node+0x1af/0x390
> [ 152.483875] ? _copy_from_iter+0x3d6/0xc70
> [ 152.484528] netlink_unicast+0x553/0x790
> [ 152.485168] ? netlink_attachskb+0x6a0/0x6a0
> [ 152.485848] ? unwind_next_frame+0x11cc/0x1a10
> [ 152.486538] ? arch_stack_walk+0x61/0xf0
> [ 152.487169] netlink_sendmsg+0x7a1/0xcb0
> [ 152.487799] ? netlink_unicast+0x790/0x790
> [ 152.488355] ? iovec_from_user.part.0+0x4d/0x220
> [ 152.488990] ? _raw_spin_lock+0x7a/0xd0
> [ 152.489598] ? netlink_unicast+0x790/0x790
> [ 152.490236] sock_sendmsg+0xc5/0x190
> [ 152.490796] ____sys_sendmsg+0x535/0x6b0
> [ 152.491394] ? import_iovec+0x7/0x10
> [ 152.491964] ? kernel_sendmsg+0x30/0x30
> [ 152.492561] ? __copy_msghdr+0x3c0/0x3c0
> [ 152.493160] ? do_syscall_64+0x3d/0x90
> [ 152.493706] ___sys_sendmsg+0xeb/0x170
> [ 152.494283] ? may_open_dev+0xd0/0xd0
> [ 152.494858] ? copy_msghdr_from_user+0x110/0x110
> [ 152.495541] ? __handle_mm_fault+0x2678/0x4ad0
> [ 152.496205] ? copy_page_range+0x2360/0x2360
> [ 152.496862] ? __fget_light+0x57/0x520
> [ 152.497449] ? mas_find+0x1c0/0x1c0
> [ 152.498026] ? sockfd_lookup_light+0x1a/0x140
> [ 152.498703] __sys_sendmsg+0xb5/0x140
> [ 152.499306] ? __sys_sendmsg_sock+0x20/0x20
> [ 152.499951] ? do_user_addr_fault+0x369/0xd80
> [ 152.500595] do_syscall_64+0x3d/0x90
> [ 152.501185] entry_SYSCALL_64_after_hwframe+0x46/0xb0
> [ 152.501917] RIP: 0033:0x7f5eb294f887
> [ 152.502494] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
> [ 152.505008] RSP: 002b:00007ffd2c708f78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> [ 152.506152] RAX: ffffffffffffffda RBX: 00000000642d9472 RCX: 00007f5eb294f887
> [ 152.507134] RDX: 0000000000000000 RSI: 00007ffd2c708fe0 RDI: 0000000000000003
> [ 152.508113] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
> [ 152.509119] R10: 00007f5eb2808708 R11: 0000000000000246 R12: 0000000000000001
> [ 152.510068] R13: 0000000000000000 R14: 00007ffd2c70d1b8 R15: 0000000000485400
> [ 152.511031] </TASK>
> [ 152.511444] Modules linked in: cls_flower sch_ingress openvswitch nsh mlx5_vdpa vringh vhost_iotlb vdpa mlx5_ib mlx5_core rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm ib_uverbs ib_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter overlay zram zsmalloc fuse [last unloaded: mlx5_core]
> [ 152.515720] ---[ end trace 0000000000000000 ]---
>
> Fixes: 08a0063df3ae ("net/sched: flower: Move filter handle initialization earlier")
> Signed-off-by: Vlad Buslov <vladbu@...dia.com>|
LGTM,
Reviewed-by: Pedro Tammela <pctammela@...atatu.com>
> ---
> net/sched/cls_flower.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
> index 475fe222a855..1844545bef37 100644
> --- a/net/sched/cls_flower.c
> +++ b/net/sched/cls_flower.c
> @@ -2210,10 +2210,10 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
> spin_lock(&tp->lock);
> if (!handle) {
> handle = 1;
> - err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
> + err = idr_alloc_u32(&head->handle_idr, NULL, &handle,
> INT_MAX, GFP_ATOMIC);
> } else {
> - err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
> + err = idr_alloc_u32(&head->handle_idr, NULL, &handle,
> handle, GFP_ATOMIC);
>
> /* Filter with specified handle was concurrently
> @@ -2378,7 +2378,7 @@ static void fl_walk(struct tcf_proto *tp, struct tcf_walker *arg,
> rcu_read_lock();
> idr_for_each_entry_continue_ul(&head->handle_idr, f, tmp, id) {
> /* don't return filters that are being deleted */
> - if (!refcount_inc_not_zero(&f->refcnt))
> + if (!f || !refcount_inc_not_zero(&f->refcnt))
> continue;
> rcu_read_unlock();
>
Powered by blists - more mailing lists