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BUG: KASAN: use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:443
Read of size 8 at addr ffff888080a502e8 by task kworker/1:7/6021

CPU: 1 UID: 0 PID: 6021 Comm: kworker/1:7 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events smc_ib_port_event_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:443
 ib_get_eth_speed+0x15e/0x7b0 drivers/infiniband/core/verbs.c:1999
 rxe_query_port+0x93/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2148 [inline]
 ib_query_port+0x170/0x830 drivers/infiniband/core/device.c:2180
 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
 smc_ib_port_event_work+0x15a/0x940 net/smc/smc_ib.c:388
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888080a53a80 pfn:0x80a50
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0002cf3a08 ffff8880b8740c00 0000000000000000
raw: ffff888080a53a80 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x446dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP), pid 23603, tgid 23603 (syz-executor), ts 785201444770, free_ts 1098239417558
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 ___kmalloc_large_node+0x4e/0x150 mm/slub.c:5598
 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:5629
 __do_kmalloc_node mm/slub.c:5645 [inline]
 __kvmalloc_node_noprof+0x6e/0x920 mm/slub.c:7134
 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:11997
 ieee80211_if_add+0x45c/0x1370 net/mac80211/iface.c:2227
 ieee80211_register_hw+0x35d9/0x4110 net/mac80211/main.c:1607
 mac80211_hwsim_new_radio+0x2f76/0x5320 drivers/net/wireless/virtual/mac80211_hwsim.c:5810
 hwsim_new_radio_nl+0xf5b/0x1bd0 drivers/net/wireless/virtual/mac80211_hwsim.c:6504
 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
page last free pid 36 tgid 36 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
 device_release+0x9e/0x1d0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x228/0x570 lib/kobject.c:737
 netdev_run_todo+0xd2c/0xea0 net/core/dev.c:11698
 ieee80211_unregister_hw+0x128/0x2c0 net/mac80211/main.c:1690
 mac80211_hwsim_del_radio+0x275/0x460 drivers/net/wireless/virtual/mac80211_hwsim.c:5916
 hwsim_exit_net+0xef4/0xfb0 drivers/net/wireless/virtual/mac80211_hwsim.c:6807
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Memory state around the buggy address:
 ffff888080a50180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888080a50200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888080a50280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                          ^
 ffff888080a50300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888080a50380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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