Re: [syzbot] Re: [syzbot] [net?] KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings

From: syzbot
Date: Thu Oct 10 2024 - 04:44:42 EST


For archival purposes, forwarding an incoming command email to
linux-kernel@xxxxxxxxxxxxxxx, syzkaller-bugs@xxxxxxxxxxxxxxxx.

***

Subject: Re: [syzbot] [net?] KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
Author: cmeiohas@xxxxxxxxxx

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git for-next

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 93c6d27b5d8f..eafdf1741582 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2062,19 +2062,14 @@ void ib_dispatch_event_clients(struct ib_event *event)
     up_read(&event->device->event_handler_rwsem);
 }

-static int iw_query_port(struct ib_device *device,
-               u32 port_num,
-               struct ib_port_attr *port_attr)
+static int iw_query_port(struct ib_device *device, u32 port_num,
+                        struct ib_port_attr *port_attr,
+                        struct net_device *netdev)
 {
     struct in_device *inetdev;
-    struct net_device *netdev;

     memset(port_attr, 0, sizeof(*port_attr));

-    netdev = ib_device_get_netdev(device, port_num);
-    if (!netdev)
-        return -ENODEV;
-
     port_attr->max_mtu = IB_MTU_4096;
     port_attr->active_mtu = ib_mtu_int_to_enum(netdev->mtu);

@@ -2097,7 +2092,6 @@ static int iw_query_port(struct ib_device *device,
         rcu_read_unlock();
     }

-    dev_put(netdev);
     return device->ops.query_port(device, port_num, port_attr);
 }

@@ -2135,13 +2129,27 @@ int ib_query_port(struct ib_device *device,
           u32 port_num,
           struct ib_port_attr *port_attr)
 {
+       struct net_device *netdev = NULL;
+       int ret;
+
     if (!rdma_is_port_valid(device, port_num))
         return -EINVAL;

+       if (rdma_protocol_iwarp(device, port_num) ||
+           rdma_protocol_roce(device, port_num)) {
+               netdev = ib_device_get_netdev(device, port_num);
+               if (!netdev)
+                       return -ENODEV;
+       }
+
     if (rdma_protocol_iwarp(device, port_num))
-        return iw_query_port(device, port_num, port_attr);
+               ret = iw_query_port(device, port_num, port_attr, netdev);
     else
-        return __ib_query_port(device, port_num, port_attr);
+               ret = __ib_query_port(device, port_num, port_attr);
+       if (netdev)
+               dev_put(netdev);
+       return ret;
+
 }
 EXPORT_SYMBOL(ib_query_port);

diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
index 75d1407db52d..c5d439bebc24 100644
--- a/drivers/infiniband/sw/rxe/rxe_net.c
+++ b/drivers/infiniband/sw/rxe/rxe_net.c
@@ -605,6 +605,7 @@ static int rxe_notify(struct notifier_block *not_blk,

     switch (event) {
     case NETDEV_UNREGISTER:
+        ib_device_set_netdev(&rxe->ib_dev, NULL, 1);
         ib_unregister_device_queued(&rxe->ib_dev);
         break;
     case NETDEV_UP:
diff --git a/drivers/infiniband/sw/siw/siw_main.c b/drivers/infiniband/sw/siw/siw_main.c
index 17abef48abcd..1b7d34798783 100644
--- a/drivers/infiniband/sw/siw/siw_main.c
+++ b/drivers/infiniband/sw/siw/siw_main.c
@@ -400,6 +400,7 @@ static int siw_netdev_event(struct notifier_block *nb, unsigned long event,
         break;

     case NETDEV_UNREGISTER:
+        ib_device_set_netdev(&sdev->base_dev, NULL, 1);
         ib_unregister_device_queued(&sdev->base_dev);
         break;


On 08/10/2024 15:24, syzbot wrote:
> External email: Use caution opening links or attachments
>
>
> Hello,
>
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:442
> Read of size 8 at addr ffff8880673be308 by task kworker/0:1/9
>
> CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.12.0-rc2-syzkaller-g615b94746a54-dirty #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> Workqueue: events smc_ib_port_event_work
> Call Trace:
> <TASK>
> __dump_stack lib/dump_stack.c:94 [inline]
> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
> print_address_description mm/kasan/report.c:377 [inline]
> print_report+0x169/0x550 mm/kasan/report.c:488
> kasan_report+0x143/0x180 mm/kasan/report.c:601
> __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:442
> ib_get_eth_speed+0x160/0x800 drivers/infiniband/core/verbs.c:1996
> rxe_query_port+0x76/0x260 drivers/infiniband/sw/rxe/rxe_verbs.c:55
> __ib_query_port drivers/infiniband/core/device.c:2105 [inline]
> ib_query_port+0x208/0x870 drivers/infiniband/core/device.c:2147
> smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
> smc_ib_port_event_work+0x14e/0xa50 net/smc/smc_ib.c:388
> process_one_work kernel/workqueue.c:3229 [inline]
> process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
> worker_thread+0x870/0xd30 kernel/workqueue.c:3391
> kthread+0x2f0/0x390 kernel/kthread.c:389
> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
> </TASK>
>
> Allocated by task 5967:
> kasan_save_stack mm/kasan/common.c:47 [inline]
> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
> poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
> __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
> kasan_kmalloc include/linux/kasan.h:257 [inline]
> __do_kmalloc_node mm/slub.c:4264 [inline]
> __kmalloc_node_noprof+0x22a/0x440 mm/slub.c:4270
> __kvmalloc_node_noprof+0x72/0x190 mm/util.c:658
> alloc_netdev_mqs+0x9b/0x1000 net/core/dev.c:11097
> rtnl_create_link+0x2f9/0xc20 net/core/rtnetlink.c:3374
> rtnl_newlink_create net/core/rtnetlink.c:3500 [inline]
> __rtnl_newlink net/core/rtnetlink.c:3730 [inline]
> rtnl_newlink+0x1423/0x20a0 net/core/rtnetlink.c:3743
> rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646
> netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550
> netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
> netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
> netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
> sock_sendmsg_nosec net/socket.c:729 [inline]
> __sock_sendmsg+0x221/0x270 net/socket.c:744
> __sys_sendto+0x39b/0x4f0 net/socket.c:2209
> __do_sys_sendto net/socket.c:2221 [inline]
> __se_sys_sendto net/socket.c:2217 [inline]
> __x64_sys_sendto+0xde/0x100 net/socket.c:2217
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Freed by task 11:
> kasan_save_stack mm/kasan/common.c:47 [inline]
> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
> kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
> poison_slab_object mm/kasan/common.c:247 [inline]
> __kasan_slab_free+0x59/0x70 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+0x1a0/0x440 mm/slub.c:4727
> device_release+0x99/0x1c0
> kobject_cleanup lib/kobject.c:689 [inline]
> kobject_release lib/kobject.c:720 [inline]
> kref_put include/linux/kref.h:65 [inline]
> kobject_put+0x22f/0x480 lib/kobject.c:737
> netdev_run_todo+0xe79/0x1000 net/core/dev.c:10816
> default_device_exit_batch+0xa24/0xaa0 net/core/dev.c:11949
> ops_exit_list net/core/net_namespace.c:178 [inline]
> cleanup_net+0x89d/0xcc0 net/core/net_namespace.c:626
> process_one_work kernel/workqueue.c:3229 [inline]
> process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
> worker_thread+0x870/0xd30 kernel/workqueue.c:3391
> kthread+0x2f0/0x390 kernel/kthread.c:389
> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>
> The buggy address belongs to the object at ffff8880673be000
> which belongs to the cache kmalloc-cg-4k of size 4096
> The buggy address is located 776 bytes inside of
> freed 4096-byte region [ffff8880673be000, ffff8880673bf000)
>
> The buggy address belongs to the physical page:
> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x673b8
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> memcg:ffff888031406a41
> flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 00fff00000000040 ffff88801ac4f500 dead000000000122 0000000000000000
> raw: 0000000000000000 0000000000040004 00000001f5000000 ffff888031406a41
> head: 00fff00000000040 ffff88801ac4f500 dead000000000122 0000000000000000
> head: 0000000000000000 0000000000040004 00000001f5000000 ffff888031406a41
> head: 00fff00000000003 ffffea00019cee01 ffffffffffffffff 0000000000000000
> head: 0000000700000008 0000000000000000 00000000ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5982, tgid 5982 (syz-executor), ts 102124010087, free_ts 96435310364
> set_page_owner include/linux/page_owner.h:32 [inline]
> post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
> prep_new_page mm/page_alloc.c:1545 [inline]
> get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
> __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
> alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
> alloc_slab_page+0x6a/0x120 mm/slub.c:2412
> allocate_slab+0x5a/0x2f0 mm/slub.c:2578
> new_slab mm/slub.c:2631 [inline]
> ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
> __slab_alloc+0x58/0xa0 mm/slub.c:3908
> __slab_alloc_node mm/slub.c:3961 [inline]
> slab_alloc_node mm/slub.c:4122 [inline]
> __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4290
> kmalloc_noprof include/linux/slab.h:878 [inline]
> kzalloc_noprof include/linux/slab.h:1014 [inline]
> snmp6_alloc_dev net/ipv6/addrconf.c:359 [inline]
> ipv6_add_dev+0x570/0x1220 net/ipv6/addrconf.c:409
> addrconf_notify+0x6a7/0x1020 net/ipv6/addrconf.c:3655
> notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
> call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
> call_netdevice_notifiers net/core/dev.c:2048 [inline]
> register_netdevice+0x167f/0x1b00 net/core/dev.c:10524
> veth_newlink+0x855/0xce0 drivers/net/veth.c:1861
> rtnl_newlink_create net/core/rtnetlink.c:3510 [inline]
> __rtnl_newlink net/core/rtnetlink.c:3730 [inline]
> rtnl_newlink+0x1591/0x20a0 net/core/rtnetlink.c:3743
> rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646
> page last free pid 5869 tgid 5869 stack trace:
> reset_page_owner include/linux/page_owner.h:25 [inline]
> free_pages_prepare mm/page_alloc.c:1108 [inline]
> free_unref_folios+0xf12/0x18d0 mm/page_alloc.c:2686
> folios_put_refs+0x76c/0x860 mm/swap.c:1007
> free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:332
> __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
> tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
> tlb_flush_mmu_free mm/mmu_gather.c:366 [inline]
> tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373
> tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465
> vms_clear_ptes+0x437/0x530 mm/vma.c:1096
> vms_complete_munmap_vmas+0x208/0x910 mm/vma.c:1140
> do_vmi_align_munmap+0x613/0x730 mm/vma.c:1349
> do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1397
> __vm_munmap+0x24c/0x480 mm/mmap.c:1600
> __do_sys_munmap mm/mmap.c:1617 [inline]
> __se_sys_munmap mm/mmap.c:1614 [inline]
> __x64_sys_munmap+0x68/0x80 mm/mmap.c:1614
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Memory state around the buggy address:
> ffff8880673be200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8880673be280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff8880673be300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff8880673be380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8880673be400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> Tested on:
>
> commit: 615b9474 RDMA/hns: Disassociate mmap pages for all uct..
> git tree: https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git for-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=131b1707980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=7cd9e7e4a8a0a15b
> dashboard link: https://syzkaller.appspot.com/bug?extid=5fe14f2ff4ccbace9a26
> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> patch: https://syzkaller.appspot.com/x/patch.diff?x=17698f9f980000
>
>