syzbot

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BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x190/0x1c0 net/ethtool/ioctl.c:444
Read of size 8 at addr ffff88807c8d22f0 by task kworker/0:1/10

CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events smc_ib_port_event_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595
 __ethtool_get_link_ksettings+0x190/0x1c0 net/ethtool/ioctl.c:444
 __ethtool_get_link_ksettings+0x144/0x1c0 net/ethtool/ioctl.c:451
 ib_get_eth_speed+0x13a/0xb40 drivers/infiniband/core/verbs.c:2055
 rxe_query_port+0x12a/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2121 [inline]
 ib_query_port drivers/infiniband/core/device.c:2153 [inline]
 ib_query_port+0x445/0x8b0 drivers/infiniband/core/device.c:2143
 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
 smc_ib_port_event_work+0x14c/0xbd0 net/smc/smc_ib.c:388
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 10585:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5295 [inline]
 __kvmalloc_node_noprof+0x360/0xa00 mm/slub.c:6828
 alloc_netdev_mqs+0xd7/0x14f0 net/core/dev.c:12076
 rtnl_create_link+0xc13/0xf80 net/core/rtnetlink.c:3670
 rtnl_newlink_create net/core/rtnetlink.c:3852 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3993 [inline]
 rtnl_newlink+0x13bd/0x2380 net/core/rtnetlink.c:4108
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6994
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 __sys_sendto+0x468/0x4b0 net/socket.c:2265
 __do_sys_sendto net/socket.c:2272 [inline]
 __se_sys_sendto net/socket.c:2268 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2268
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 48:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kfree+0x223/0x6c0 mm/slub.c:6561
 device_release+0xd2/0x270 drivers/base/core.c:2566
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1f7/0x640 lib/kobject.c:737
 netdev_run_todo+0x817/0x12c0 net/core/dev.c:11777
 default_device_exit_batch+0x94b/0xc60 net/core/dev.c:13120
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x363/0xab0 net/core/net_namespace.c:252
 cleanup_net+0x499/0x920 net/core/net_namespace.c:702
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff88807c8d2000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 752 bytes inside of
 freed 4096-byte region [ffff88807c8d2000, ffff88807c8d3000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c8d0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88807c8d1011
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813fea4500 dead000000000100 dead000000000122
raw: 0000000000000000 0000200000040004 00000000f5000000 ffff88807c8d1011
head: 00fff00000000040 ffff88813fea4500 dead000000000100 dead000000000122
head: 0000000000000000 0000200000040004 00000000f5000000 ffff88807c8d1011
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
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 5962, tgid 5962 (syz-executor), ts 122346605371, free_ts 52825419439
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab mm/slub.c:3467 [inline]
 new_slab+0xa6/0x6c0 mm/slub.c:3525
 refill_objects+0x277/0x420 mm/slub.c:7251
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5410
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 snmp6_alloc_dev net/ipv6/addrconf.c:362 [inline]
 ipv6_add_dev+0x670/0x1520 net/ipv6/addrconf.c:413
 addrconf_notify+0x5db/0x1ba0 net/ipv6/addrconf.c:3662
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x16e6/0x2210 net/core/dev.c:11508
 register_netdev+0x34/0x50 net/core/dev.c:11586
 sit_init_net+0x2c0/0x5e0 net/ipv6/sit.c:1860
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
page last free pid 5706 tgid 5706 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4905
 vm_area_dup+0x27/0x8e0 mm/vma_init.c:123
 __split_vma+0x18c/0xd90 mm/vma.c:516
 vms_gather_munmap_vmas+0x1d2/0x1720 mm/vma.c:1427
 __mmap_setup mm/vma.c:2439 [inline]
 __mmap_region+0x4aa/0x2da0 mm/vma.c:2753
 mmap_region+0x35d/0x620 mm/vma.c:2856
 do_mmap+0xc63/0x12f0 mm/mmap.c:560
 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581
 ksys_mmap_pgoff+0x3cb/0x610 mm/mmap.c:606
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807c8d2180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807c8d2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807c8d2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff88807c8d2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807c8d2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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