| Message ID | 20241015-net-mptcp-uaf-pm-rm-v1-1-c4ee5d987a64@kernel.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Delegated to: | Matthieu Baerts |
| Headers | show |
| Series | [net] mptcp: pm: fix UaF read in mptcp_pm_nl_rm_addr_or_subflow | expand |
| Context | Check | Description |
|---|---|---|
| matttbe/build | success | Build and static analysis OK |
| matttbe/checkpatch | warning | total: 0 errors, 1 warnings, 0 checks, 13 lines checked |
| matttbe/shellcheck | success | MPTCP selftests files have not been modified |
| matttbe/KVM_Validation__normal | success | Success! ✅ |
| matttbe/KVM_Validation__debug | success | Success! ✅ |
| matttbe/KVM_Validation__btf__only_bpftest_all_ | success | Success! ✅ |
Hi Matthieu,
Thank you for your modifications, that's great!
Our CI did some validations and here is its report:
- KVM Validation: normal: Success! ✅
- KVM Validation: debug: Success! ✅
- KVM Validation: btf (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/11342595780
Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/10840610d522
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=899195
If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:
$ cd [kernel source code]
$ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
--pull always mptcp/mptcp-upstream-virtme-docker:latest \
auto-normal
For more details:
https://github.com/multipath-tcp/mptcp-upstream-virtme-docker
Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)
Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)
On 10/15/24 10:38, Matthieu Baerts (NGI0) wrote: > Syzkaller reported this splat: > > ================================================================== > BUG: KASAN: slab-use-after-free in mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881 > Read of size 4 at addr ffff8880569ac858 by task syz.1.2799/14662 > > CPU: 0 UID: 0 PID: 14662 Comm: syz.1.2799 Not tainted 6.12.0-rc2-syzkaller-00307-g36c254515dc6 #0 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 > print_address_description mm/kasan/report.c:377 [inline] > print_report+0xc3/0x620 mm/kasan/report.c:488 > kasan_report+0xd9/0x110 mm/kasan/report.c:601 > mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881 > mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:914 [inline] > mptcp_nl_remove_id_zero_address+0x305/0x4a0 net/mptcp/pm_netlink.c:1572 > mptcp_pm_nl_del_addr_doit+0x5c9/0x770 net/mptcp/pm_netlink.c:1603 > genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 > genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] > genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 > netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2551 > genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 > netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] > netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 > netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 > sock_sendmsg_nosec net/socket.c:729 [inline] > __sock_sendmsg net/socket.c:744 [inline] > ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2607 > ___sys_sendmsg+0x135/0x1e0 net/socket.c:2661 > __sys_sendmsg+0x117/0x1f0 net/socket.c:2690 > do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] > __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 > do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 > entry_SYSENTER_compat_after_hwframe+0x84/0x8e > RIP: 0023:0xf7fe4579 > Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 > RSP: 002b:00000000f574556c EFLAGS: 00000296 ORIG_RAX: 0000000000000172 > RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000020000140 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > </TASK> > > Allocated by task 5387: > kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > kmalloc_noprof include/linux/slab.h:878 [inline] > kzalloc_noprof include/linux/slab.h:1014 [inline] > subflow_create_ctx+0x87/0x2a0 net/mptcp/subflow.c:1803 > subflow_ulp_init+0xc3/0x4d0 net/mptcp/subflow.c:1956 > __tcp_set_ulp net/ipv4/tcp_ulp.c:146 [inline] > tcp_set_ulp+0x326/0x7f0 net/ipv4/tcp_ulp.c:167 > mptcp_subflow_create_socket+0x4ae/0x10a0 net/mptcp/subflow.c:1764 > __mptcp_subflow_connect+0x3cc/0x1490 net/mptcp/subflow.c:1592 > mptcp_pm_create_subflow_or_signal_addr+0xbda/0x23a0 net/mptcp/pm_netlink.c:642 > mptcp_pm_nl_fully_established net/mptcp/pm_netlink.c:650 [inline] > mptcp_pm_nl_work+0x3a1/0x4f0 net/mptcp/pm_netlink.c:943 > mptcp_worker+0x15a/0x1240 net/mptcp/protocol.c:2777 > process_one_work+0x958/0x1b30 kernel/workqueue.c:3229 > process_scheduled_works kernel/workqueue.c:3310 [inline] > worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 > kthread+0x2c1/0x3a0 kernel/kthread.c:389 > ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Freed by task 113: > kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 > poison_slab_object mm/kasan/common.c:247 [inline] > __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 > kasan_slab_free include/linux/kasan.h:230 [inline] > slab_free_hook mm/slub.c:2342 [inline] > slab_free mm/slub.c:4579 [inline] > kfree+0x14f/0x4b0 mm/slub.c:4727 > kvfree+0x47/0x50 mm/util.c:701 > kvfree_rcu_list+0xf5/0x2c0 kernel/rcu/tree.c:3423 > kvfree_rcu_drain_ready kernel/rcu/tree.c:3563 [inline] > kfree_rcu_monitor+0x503/0x8b0 kernel/rcu/tree.c:3632 > kfree_rcu_shrink_scan+0x245/0x3a0 kernel/rcu/tree.c:3966 > do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435 > shrink_slab+0x32b/0x12a0 mm/shrinker.c:662 > shrink_one+0x47e/0x7b0 mm/vmscan.c:4818 > shrink_many mm/vmscan.c:4879 [inline] > lru_gen_shrink_node mm/vmscan.c:4957 [inline] > shrink_node+0x2452/0x39d0 mm/vmscan.c:5937 > kswapd_shrink_node mm/vmscan.c:6765 [inline] > balance_pgdat+0xc19/0x18f0 mm/vmscan.c:6957 > kswapd+0x5ea/0xbf0 mm/vmscan.c:7226 > kthread+0x2c1/0x3a0 kernel/kthread.c:389 > ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Last potentially related work creation: > kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 > __kasan_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:541 > kvfree_call_rcu+0x74/0xbe0 kernel/rcu/tree.c:3810 > subflow_ulp_release+0x2ae/0x350 net/mptcp/subflow.c:2009 > tcp_cleanup_ulp+0x7c/0x130 net/ipv4/tcp_ulp.c:124 > tcp_v4_destroy_sock+0x1c5/0x6a0 net/ipv4/tcp_ipv4.c:2541 > inet_csk_destroy_sock+0x1a3/0x440 net/ipv4/inet_connection_sock.c:1293 > tcp_done+0x252/0x350 net/ipv4/tcp.c:4870 > tcp_rcv_state_process+0x379b/0x4f30 net/ipv4/tcp_input.c:6933 > tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1938 > sk_backlog_rcv include/net/sock.h:1115 [inline] > __release_sock+0x31b/0x400 net/core/sock.c:3072 > __tcp_close+0x4f3/0xff0 net/ipv4/tcp.c:3142 > __mptcp_close_ssk+0x331/0x14d0 net/mptcp/protocol.c:2489 > mptcp_close_ssk net/mptcp/protocol.c:2543 [inline] > mptcp_close_ssk+0x150/0x220 net/mptcp/protocol.c:2526 > mptcp_pm_nl_rm_addr_or_subflow+0x2be/0xcc0 net/mptcp/pm_netlink.c:878 > mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:914 [inline] > mptcp_nl_remove_id_zero_address+0x305/0x4a0 net/mptcp/pm_netlink.c:1572 > mptcp_pm_nl_del_addr_doit+0x5c9/0x770 net/mptcp/pm_netlink.c:1603 > genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 > genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] > genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 > netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2551 > genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 > netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] > netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 > netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 > sock_sendmsg_nosec net/socket.c:729 [inline] > __sock_sendmsg net/socket.c:744 [inline] > ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2607 > ___sys_sendmsg+0x135/0x1e0 net/socket.c:2661 > __sys_sendmsg+0x117/0x1f0 net/socket.c:2690 > do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] > __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 > do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 > entry_SYSENTER_compat_after_hwframe+0x84/0x8e > > The buggy address belongs to the object at ffff8880569ac800 > which belongs to the cache kmalloc-512 of size 512 > The buggy address is located 88 bytes inside of > freed 512-byte region [ffff8880569ac800, ffff8880569aca00) > > The buggy address belongs to the physical page: > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x569ac > head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 > flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) > page_type: f5(slab) > raw: 04fff00000000040 ffff88801ac42c80 dead000000000100 dead000000000122 > raw: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 > head: 04fff00000000040 ffff88801ac42c80 dead000000000100 dead000000000122 > head: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 > head: 04fff00000000002 ffffea00015a6b01 ffffffffffffffff 0000000000000000 > head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 10238, tgid 10238 (kworker/u32:6), ts 597403252405, free_ts 597177952947 > set_page_owner include/linux/page_owner.h:32 [inline] > post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1537 > prep_new_page mm/page_alloc.c:1545 [inline] > get_page_from_freelist+0x101e/0x3070 mm/page_alloc.c:3457 > __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4733 > alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2265 > alloc_slab_page mm/slub.c:2412 [inline] > allocate_slab mm/slub.c:2578 [inline] > new_slab+0x2ba/0x3f0 mm/slub.c:2631 > ___slab_alloc+0xd1d/0x16f0 mm/slub.c:3818 > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908 > __slab_alloc_node mm/slub.c:3961 [inline] > slab_alloc_node mm/slub.c:4122 [inline] > __kmalloc_cache_noprof+0x2c5/0x310 mm/slub.c:4290 > kmalloc_noprof include/linux/slab.h:878 [inline] > kzalloc_noprof include/linux/slab.h:1014 [inline] > mld_add_delrec net/ipv6/mcast.c:743 [inline] > igmp6_leave_group net/ipv6/mcast.c:2625 [inline] > igmp6_group_dropped+0x4ab/0xe40 net/ipv6/mcast.c:723 > __ipv6_dev_mc_dec+0x281/0x360 net/ipv6/mcast.c:979 > addrconf_leave_solict net/ipv6/addrconf.c:2253 [inline] > __ipv6_ifa_notify+0x3f6/0xc30 net/ipv6/addrconf.c:6283 > addrconf_ifdown.isra.0+0xef9/0x1a20 net/ipv6/addrconf.c:3982 > addrconf_notify+0x220/0x19c0 net/ipv6/addrconf.c:3781 > notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 > call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996 > call_netdevice_notifiers_extack net/core/dev.c:2034 [inline] > call_netdevice_notifiers net/core/dev.c:2048 [inline] > dev_close_many+0x333/0x6a0 net/core/dev.c:1589 > page last free pid 13136 tgid 13136 stack trace: > reset_page_owner include/linux/page_owner.h:25 [inline] > free_pages_prepare mm/page_alloc.c:1108 [inline] > free_unref_page+0x5f4/0xdc0 mm/page_alloc.c:2638 > stack_depot_save_flags+0x2da/0x900 lib/stackdepot.c:666 > kasan_save_stack+0x42/0x60 mm/kasan/common.c:48 > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > unpoison_slab_object mm/kasan/common.c:319 [inline] > __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 > kasan_slab_alloc include/linux/kasan.h:247 [inline] > slab_post_alloc_hook mm/slub.c:4085 [inline] > slab_alloc_node mm/slub.c:4134 [inline] > kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4141 > skb_clone+0x190/0x3f0 net/core/skbuff.c:2084 > do_one_broadcast net/netlink/af_netlink.c:1462 [inline] > netlink_broadcast_filtered+0xb11/0xef0 net/netlink/af_netlink.c:1540 > netlink_broadcast+0x39/0x50 net/netlink/af_netlink.c:1564 > uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline] > kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] > kobject_uevent_env+0xacd/0x1670 lib/kobject_uevent.c:608 > device_del+0x623/0x9f0 drivers/base/core.c:3882 > snd_card_disconnect.part.0+0x58a/0x7c0 sound/core/init.c:546 > snd_card_disconnect+0x1f/0x30 sound/core/init.c:495 > snd_usx2y_disconnect+0xe9/0x1f0 sound/usb/usx2y/usbusx2y.c:417 > usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461 > device_remove drivers/base/dd.c:569 [inline] > device_remove+0x122/0x170 drivers/base/dd.c:561 > > That's because 'subflow' is used just after 'mptcp_close_ssk(subflow)', > which will initiate the release of its memory. Even if it is very likely > the release and the re-utilisation will be done later on, it is of > course better to avoid any issues and read the content of 'subflow' > before closing it. > > Fixes: 1c1f72137598 ("mptcp: pm: only decrement add_addr_accepted for MPJ req") > Cc: stable@vger.kernel.org > Reported-by: syzbot+3c8b7a8e7df6a2a226ca@syzkaller.appspotmail.com > Closes: https://lore.kernel.org/670d7337.050a0220.4cbc0.004f.GAE@google.com > Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> > --- > net/mptcp/pm_netlink.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c > index f6f0a38a0750f82bc909f02a75beec980d951f1f..4dd61284afc5f7f70708827056fb4530c8879502 100644 > --- a/net/mptcp/pm_netlink.c > +++ b/net/mptcp/pm_netlink.c > @@ -873,12 +873,12 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, > i, rm_id, id, remote_id, msk->mpc_endpoint_id); > spin_unlock_bh(&msk->pm.lock); > mptcp_subflow_shutdown(sk, ssk, how); > + removed |= subflow->request_join; > > /* the following takes care of updating the subflows counter */ > mptcp_close_ssk(sk, ssk, subflow); > spin_lock_bh(&msk->pm.lock); > > - removed |= subflow->request_join; > if (rm_type == MPTCP_MIB_RMSUBFLOW) > __MPTCP_INC_STATS(sock_net(sk), rm_type); > } > Acked-by: Paolo Abeni <pabeni@redhat.com>
Hello: This patch was applied to netdev/net.git (main) by Paolo Abeni <pabeni@redhat.com>: On Tue, 15 Oct 2024 10:38:47 +0200 you wrote: > Syzkaller reported this splat: > > ================================================================== > BUG: KASAN: slab-use-after-free in mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881 > Read of size 4 at addr ffff8880569ac858 by task syz.1.2799/14662 > > CPU: 0 UID: 0 PID: 14662 Comm: syz.1.2799 Not tainted 6.12.0-rc2-syzkaller-00307-g36c254515dc6 #0 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 > print_address_description mm/kasan/report.c:377 [inline] > print_report+0xc3/0x620 mm/kasan/report.c:488 > kasan_report+0xd9/0x110 mm/kasan/report.c:601 > mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881 > mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:914 [inline] > mptcp_nl_remove_id_zero_address+0x305/0x4a0 net/mptcp/pm_netlink.c:1572 > mptcp_pm_nl_del_addr_doit+0x5c9/0x770 net/mptcp/pm_netlink.c:1603 > genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 > genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] > genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 > netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2551 > genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 > netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] > netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 > netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 > sock_sendmsg_nosec net/socket.c:729 [inline] > __sock_sendmsg net/socket.c:744 [inline] > ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2607 > ___sys_sendmsg+0x135/0x1e0 net/socket.c:2661 > __sys_sendmsg+0x117/0x1f0 net/socket.c:2690 > do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] > __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 > do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 > entry_SYSENTER_compat_after_hwframe+0x84/0x8e > RIP: 0023:0xf7fe4579 > Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 > RSP: 002b:00000000f574556c EFLAGS: 00000296 ORIG_RAX: 0000000000000172 > RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000020000140 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > </TASK> > > [...] Here is the summary with links: - [net] mptcp: pm: fix UaF read in mptcp_pm_nl_rm_addr_or_subflow https://git.kernel.org/netdev/net/c/7decd1f5904a You are awesome, thank you!
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index f6f0a38a0750f82bc909f02a75beec980d951f1f..4dd61284afc5f7f70708827056fb4530c8879502 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -873,12 +873,12 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, i, rm_id, id, remote_id, msk->mpc_endpoint_id); spin_unlock_bh(&msk->pm.lock); mptcp_subflow_shutdown(sk, ssk, how); + removed |= subflow->request_join; /* the following takes care of updating the subflows counter */ mptcp_close_ssk(sk, ssk, subflow); spin_lock_bh(&msk->pm.lock); - removed |= subflow->request_join; if (rm_type == MPTCP_MIB_RMSUBFLOW) __MPTCP_INC_STATS(sock_net(sk), rm_type); }
Syzkaller reported this splat: ================================================================== BUG: KASAN: slab-use-after-free in mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881 Read of size 4 at addr ffff8880569ac858 by task syz.1.2799/14662 CPU: 0 UID: 0 PID: 14662 Comm: syz.1.2799 Not tainted 6.12.0-rc2-syzkaller-00307-g36c254515dc6 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881 mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:914 [inline] mptcp_nl_remove_id_zero_address+0x305/0x4a0 net/mptcp/pm_netlink.c:1572 mptcp_pm_nl_del_addr_doit+0x5c9/0x770 net/mptcp/pm_netlink.c:1603 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2551 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2607 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2661 __sys_sendmsg+0x117/0x1f0 net/socket.c:2690 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fe4579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f574556c EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000020000140 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Allocated by task 5387: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] subflow_create_ctx+0x87/0x2a0 net/mptcp/subflow.c:1803 subflow_ulp_init+0xc3/0x4d0 net/mptcp/subflow.c:1956 __tcp_set_ulp net/ipv4/tcp_ulp.c:146 [inline] tcp_set_ulp+0x326/0x7f0 net/ipv4/tcp_ulp.c:167 mptcp_subflow_create_socket+0x4ae/0x10a0 net/mptcp/subflow.c:1764 __mptcp_subflow_connect+0x3cc/0x1490 net/mptcp/subflow.c:1592 mptcp_pm_create_subflow_or_signal_addr+0xbda/0x23a0 net/mptcp/pm_netlink.c:642 mptcp_pm_nl_fully_established net/mptcp/pm_netlink.c:650 [inline] mptcp_pm_nl_work+0x3a1/0x4f0 net/mptcp/pm_netlink.c:943 mptcp_worker+0x15a/0x1240 net/mptcp/protocol.c:2777 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 113: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x14f/0x4b0 mm/slub.c:4727 kvfree+0x47/0x50 mm/util.c:701 kvfree_rcu_list+0xf5/0x2c0 kernel/rcu/tree.c:3423 kvfree_rcu_drain_ready kernel/rcu/tree.c:3563 [inline] kfree_rcu_monitor+0x503/0x8b0 kernel/rcu/tree.c:3632 kfree_rcu_shrink_scan+0x245/0x3a0 kernel/rcu/tree.c:3966 do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435 shrink_slab+0x32b/0x12a0 mm/shrinker.c:662 shrink_one+0x47e/0x7b0 mm/vmscan.c:4818 shrink_many mm/vmscan.c:4879 [inline] lru_gen_shrink_node mm/vmscan.c:4957 [inline] shrink_node+0x2452/0x39d0 mm/vmscan.c:5937 kswapd_shrink_node mm/vmscan.c:6765 [inline] balance_pgdat+0xc19/0x18f0 mm/vmscan.c:6957 kswapd+0x5ea/0xbf0 mm/vmscan.c:7226 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:541 kvfree_call_rcu+0x74/0xbe0 kernel/rcu/tree.c:3810 subflow_ulp_release+0x2ae/0x350 net/mptcp/subflow.c:2009 tcp_cleanup_ulp+0x7c/0x130 net/ipv4/tcp_ulp.c:124 tcp_v4_destroy_sock+0x1c5/0x6a0 net/ipv4/tcp_ipv4.c:2541 inet_csk_destroy_sock+0x1a3/0x440 net/ipv4/inet_connection_sock.c:1293 tcp_done+0x252/0x350 net/ipv4/tcp.c:4870 tcp_rcv_state_process+0x379b/0x4f30 net/ipv4/tcp_input.c:6933 tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1938 sk_backlog_rcv include/net/sock.h:1115 [inline] __release_sock+0x31b/0x400 net/core/sock.c:3072 __tcp_close+0x4f3/0xff0 net/ipv4/tcp.c:3142 __mptcp_close_ssk+0x331/0x14d0 net/mptcp/protocol.c:2489 mptcp_close_ssk net/mptcp/protocol.c:2543 [inline] mptcp_close_ssk+0x150/0x220 net/mptcp/protocol.c:2526 mptcp_pm_nl_rm_addr_or_subflow+0x2be/0xcc0 net/mptcp/pm_netlink.c:878 mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:914 [inline] mptcp_nl_remove_id_zero_address+0x305/0x4a0 net/mptcp/pm_netlink.c:1572 mptcp_pm_nl_del_addr_doit+0x5c9/0x770 net/mptcp/pm_netlink.c:1603 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2551 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2607 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2661 __sys_sendmsg+0x117/0x1f0 net/socket.c:2690 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff8880569ac800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 88 bytes inside of freed 512-byte region [ffff8880569ac800, ffff8880569aca00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x569ac head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801ac42c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 04fff00000000040 ffff88801ac42c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 04fff00000000002 ffffea00015a6b01 ffffffffffffffff 0000000000000000 head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 10238, tgid 10238 (kworker/u32:6), ts 597403252405, free_ts 597177952947 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x101e/0x3070 mm/page_alloc.c:3457 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2412 [inline] allocate_slab mm/slub.c:2578 [inline] new_slab+0x2ba/0x3f0 mm/slub.c:2631 ___slab_alloc+0xd1d/0x16f0 mm/slub.c:3818 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] __kmalloc_cache_noprof+0x2c5/0x310 mm/slub.c:4290 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] mld_add_delrec net/ipv6/mcast.c:743 [inline] igmp6_leave_group net/ipv6/mcast.c:2625 [inline] igmp6_group_dropped+0x4ab/0xe40 net/ipv6/mcast.c:723 __ipv6_dev_mc_dec+0x281/0x360 net/ipv6/mcast.c:979 addrconf_leave_solict net/ipv6/addrconf.c:2253 [inline] __ipv6_ifa_notify+0x3f6/0xc30 net/ipv6/addrconf.c:6283 addrconf_ifdown.isra.0+0xef9/0x1a20 net/ipv6/addrconf.c:3982 addrconf_notify+0x220/0x19c0 net/ipv6/addrconf.c:3781 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline] call_netdevice_notifiers net/core/dev.c:2048 [inline] dev_close_many+0x333/0x6a0 net/core/dev.c:1589 page last free pid 13136 tgid 13136 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0x5f4/0xdc0 mm/page_alloc.c:2638 stack_depot_save_flags+0x2da/0x900 lib/stackdepot.c:666 kasan_save_stack+0x42/0x60 mm/kasan/common.c:48 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4141 skb_clone+0x190/0x3f0 net/core/skbuff.c:2084 do_one_broadcast net/netlink/af_netlink.c:1462 [inline] netlink_broadcast_filtered+0xb11/0xef0 net/netlink/af_netlink.c:1540 netlink_broadcast+0x39/0x50 net/netlink/af_netlink.c:1564 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] kobject_uevent_env+0xacd/0x1670 lib/kobject_uevent.c:608 device_del+0x623/0x9f0 drivers/base/core.c:3882 snd_card_disconnect.part.0+0x58a/0x7c0 sound/core/init.c:546 snd_card_disconnect+0x1f/0x30 sound/core/init.c:495 snd_usx2y_disconnect+0xe9/0x1f0 sound/usb/usx2y/usbusx2y.c:417 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:569 [inline] device_remove+0x122/0x170 drivers/base/dd.c:561 That's because 'subflow' is used just after 'mptcp_close_ssk(subflow)', which will initiate the release of its memory. Even if it is very likely the release and the re-utilisation will be done later on, it is of course better to avoid any issues and read the content of 'subflow' before closing it. Fixes: 1c1f72137598 ("mptcp: pm: only decrement add_addr_accepted for MPJ req") Cc: stable@vger.kernel.org Reported-by: syzbot+3c8b7a8e7df6a2a226ca@syzkaller.appspotmail.com Closes: https://lore.kernel.org/670d7337.050a0220.4cbc0.004f.GAE@google.com Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> --- net/mptcp/pm_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: 25c12b459db8365fee84b63f3dd7910f70627f29 change-id: 20241015-net-mptcp-uaf-pm-rm-7810dfa3e559 Best regards,