==================================================================
BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:442
Read of size 8 at addr ffff888035fa82e8 by task kworker/0:6/5996

CPU: 0 UID: 0 PID: 5996 Comm: kworker/0:6 Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:410 [inline]
 print_report+0x16b/0x5a0 mm/kasan/report.c:510
 kasan_report+0x143/0x180 mm/kasan/report.c:623
 __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+0x95/0x3b0 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2095 [inline]
 ib_query_port+0x166/0x7d0 drivers/infiniband/core/device.c:2127
 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
 smc_ib_port_event_work+0x14e/0xa90 net/smc/smc_ib.c:388
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5836:
 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:260 [inline]
 __do_kmalloc_node mm/slub.c:4308 [inline]
 __kvmalloc_node_noprof+0x30f/0x580 mm/slub.c:4987
 alloc_netdev_mqs+0xa4/0x1210 net/core/dev.c:11473
 rtnl_create_link+0x2f9/0xc90 net/core/rtnetlink.c:3610
 rtnl_newlink_create+0x210/0xa40 net/core/rtnetlink.c:3786
 __rtnl_newlink net/core/rtnetlink.c:3912 [inline]
 rtnl_newlink+0x17cc/0x1d30 net/core/rtnetlink.c:4027
 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6917
 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2543
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x8b3/0xca0 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:733
 __sys_sendto+0x363/0x4c0 net/socket.c:2187
 __do_sys_sendto net/socket.c:2194 [inline]
 __se_sys_sendto net/socket.c:2190 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2190
 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 6615:
 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:576
 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:233 [inline]
 slab_free_hook mm/slub.c:2367 [inline]
 slab_free mm/slub.c:4623 [inline]
 kfree+0x196/0x430 mm/slub.c:4816
 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+0xd9d/0xf30 net/core/dev.c:11174
 default_device_exit_batch+0x804/0x880 net/core/dev.c:12373
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x8ad/0xd60 net/core/net_namespace.c:652
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888035fa8000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 744 bytes inside of
 freed 4096-byte region [ffff888035fa8000, ffff888035fa9000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x35fa8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b04f500 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b04f500 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000d7ea01 ffffffffffffffff 0000000000000000
head: 0000000000000008 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 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5836, tgid 5836 (syz-executor), ts 98601218641, free_ts 98521600044
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1629
 prep_new_page mm/page_alloc.c:1637 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3555
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4817
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2437 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2601
 new_slab mm/slub.c:2654 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3840
 __slab_alloc+0x58/0xa0 mm/slub.c:3930
 __slab_alloc_node mm/slub.c:4005 [inline]
 slab_alloc_node mm/slub.c:4166 [inline]
 __do_kmalloc_node mm/slub.c:4307 [inline]
 __kvmalloc_node_noprof+0x3e2/0x580 mm/slub.c:4987
 alloc_netdev_mqs+0xa4/0x1210 net/core/dev.c:11473
 rtnl_create_link+0x2f9/0xc90 net/core/rtnetlink.c:3610
 rtnl_newlink_create+0x210/0xa40 net/core/rtnetlink.c:3786
 __rtnl_newlink net/core/rtnetlink.c:3912 [inline]
 rtnl_newlink+0x17cc/0x1d30 net/core/rtnetlink.c:4027
 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6917
 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2543
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x8b3/0xca0 net/netlink/af_netlink.c:1892
page last free pid 5836 tgid 5836 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1205 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2738
 __slab_free+0x2c2/0x380 mm/slub.c:4534
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4129 [inline]
 slab_alloc_node mm/slub.c:4178 [inline]
 kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4230
 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1331 [inline]
 nlmsg_new include/net/netlink.h:1018 [inline]
 netlink_ack+0x145/0xa60 net/netlink/af_netlink.c:2480
 netlink_rcv_skb+0x294/0x480 net/netlink/af_netlink.c:2549
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x8b3/0xca0 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:733
 __sys_sendto+0x363/0x4c0 net/socket.c:2187
 __do_sys_sendto net/socket.c:2194 [inline]
 __se_sys_sendto net/socket.c:2190 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2190
 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:
 ffff888035fa8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888035fa8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888035fa8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff888035fa8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888035fa8380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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