Extracting prog: 6m54.573534858s
Minimizing prog: 37m26.476997754s
Simplifying prog options: 14m14.933383178s
Extracting C: 5m9.76670209s
Simplifying C: 0s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
detailed listing:
executing program 0:
r0 = socket$nl_rdma(0x10, 0x3, 0x14)
sendmsg$RDMA_NLDEV_CMD_NEWLINK(r0, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000100)={&(0x7f00000000c0)={0x38, 0x1403, 0x1, 0x70bd28, 0x0, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4000011}, 0x0)

program did not crash
single: failed to extract reproducer
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
detailed listing:
executing program 0:
r0 = socket$nl_rdma(0x10, 0x3, 0x14)
sendmsg$RDMA_NLDEV_CMD_NEWLINK(r0, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000100)={&(0x7f00000000c0)={0x38, 0x1403, 0x1, 0x70bd28, 0x0, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4000011}, 0x0)

program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
single: successfully extracted reproducer
found reproducer with 2 syscalls
minimizing guilty program
testing program (duration=7m20.74226299s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma
detailed listing:
executing program 0:
socket$nl_rdma(0x10, 0x3, 0x14)

program did not crash
testing program (duration=7m20.74226299s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): sendmsg$RDMA_NLDEV_CMD_NEWLINK
detailed listing:
executing program 0:
sendmsg$RDMA_NLDEV_CMD_NEWLINK(0xffffffffffffffff, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000100)={&(0x7f00000000c0)={0x38, 0x1403, 0x1, 0x70bd28, 0x0, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4000011}, 0x0)

program did not crash
testing program (duration=7m20.74226299s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
detailed listing:
executing program 0:
r0 = socket$nl_rdma(0x10, 0x3, 0x14)
sendmsg$RDMA_NLDEV_CMD_NEWLINK(r0, 0x0, 0x0)

program did not crash
testing program (duration=7m20.74226299s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
detailed listing:
executing program 0:
r0 = socket$nl_rdma(0x10, 0x3, 0x14)
sendmsg$RDMA_NLDEV_CMD_NEWLINK(r0, &(0x7f0000000140)={0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x4000011}, 0x0)

program did not crash
testing program (duration=7m20.74226299s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
detailed listing:
executing program 0:
r0 = socket$nl_rdma(0x10, 0x3, 0x14)
sendmsg$RDMA_NLDEV_CMD_NEWLINK(r0, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000100)={0x0}, 0x1, 0x0, 0x0, 0x4000011}, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=7m20.74226299s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
simplifying guilty program options
testing program (duration=7m20.74226299s, {Threaded:false Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
detailed listing:
executing program 0:
r0 = socket$nl_rdma(0x10, 0x3, 0x14)
sendmsg$RDMA_NLDEV_CMD_NEWLINK(r0, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000100)={&(0x7f00000000c0)={0x38, 0x1403, 0x1, 0x70bd28, 0x0, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4000011}, 0x0)

program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
extracting C reproducer
testing compiled C program (duration=7m20.74226299s, {Threaded:false Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
testing program (duration=7m20.74226299s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
detailed listing:
executing program 0:
r0 = socket$nl_rdma(0x10, 0x3, 0x14)
sendmsg$RDMA_NLDEV_CMD_NEWLINK(r0, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000100)={&(0x7f00000000c0)={0x38, 0x1403, 0x1, 0x70bd28, 0x0, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4000011}, 0x0)

program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
extracting C reproducer
testing compiled C program (duration=7m20.74226299s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_rdma-sendmsg$RDMA_NLDEV_CMD_NEWLINK
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
reproducing took 1h3m45.981925027s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:443
Read of size 8 at addr ffff8880563522e8 by task kworker/0:4/5520

CPU: 0 UID: 0 PID: 5520 Comm: kworker/0:4 Not tainted 6.15.0-syzkaller-10402-g4cb6c8af8591 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:443
 ib_get_eth_speed+0x15e/0x7b0 drivers/infiniband/core/verbs.c:1996
 rxe_query_port+0x93/0x3b0 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2111 [inline]
 ib_query_port+0x16d/0x830 drivers/infiniband/core/device.c:2143
 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:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 6144:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kvmalloc_node_noprof+0x314/0x600 mm/slub.c:5012
 alloc_netdev_mqs+0xa6/0x11e0 net/core/dev.c:11710
 rtnl_create_link+0x31f/0xd10 net/core/rtnetlink.c:3631
 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3813
 __rtnl_newlink net/core/rtnetlink.c:3940 [inline]
 rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:727
 __sys_sendto+0x3bd/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1035:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x18e/0x440 mm/slub.c:4841
 device_release+0x9c/0x1c0 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+0x22b/0x480 lib/kobject.c:737
 netdev_run_todo+0xd2e/0xea0 net/core/dev.c:11411
 default_device_exit_batch+0x81e/0x890 net/core/dev.c:12644
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x525/0x990 net/core/net_namespace.c:253
 cleanup_net+0x4c5/0x8a0 net/core/net_namespace.c:686
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 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 ffff888056352000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 744 bytes inside of
 freed 4096-byte region [ffff888056352000, ffff888056353000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x56350
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880336d0e41
anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801a44b500 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000000f5000000 ffff8880336d0e41
head: 04fff00000000040 ffff88801a44b500 0000000000000000 dead000000000001
head: 0000000000000000 0000000000040004 00000000f5000000 ffff8880336d0e41
head: 04fff00000000003 ffffea000158d401 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 5383, tgid 5383 (syz-executor), ts 326956863841, free_ts 323055098285
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1710
 prep_new_page mm/page_alloc.c:1718 [inline]
 get_page_from_freelist+0x21e0/0x22c0 mm/page_alloc.c:3680
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2618
 new_slab mm/slub.c:2672 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
 __slab_alloc mm/slub.c:3948 [inline]
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1376
 __addrconf_sysctl_register+0x398/0x530 net/ipv6/addrconf.c:7248
 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7296
 ipv6_add_dev+0xd46/0x1370 net/ipv6/addrconf.c:458
 addrconf_notify+0x794/0x1010 net/ipv6/addrconf.c:3654
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 register_netdevice+0x1608/0x1ae0 net/core/dev.c:11142
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:964 [inline]
 nsim_create+0xb19/0xef0 drivers/net/netdevsim/netdev.c:1032
 __nsim_dev_port_add+0x70a/0xb20 drivers/net/netdevsim/dev.c:1393
page last free pid 5357 tgid 5357 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1254 [inline]
 free_unref_folios+0xcc9/0x1550 mm/page_alloc.c:2774
 folios_put_refs+0x559/0x640 mm/swap.c:992
 free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:266
 __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:397 [inline]
 tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:496
 vms_clear_ptes+0x42c/0x540 mm/vma.c:1191
 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1233
 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1492
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1540
 __vm_munmap+0x23b/0x3d0 mm/vma.c:3014
 __do_sys_munmap mm/mmap.c:1084 [inline]
 __se_sys_munmap mm/mmap.c:1081 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056352180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056352200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888056352280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff888056352300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056352380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

final repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:443
Read of size 8 at addr ffff8880563522e8 by task kworker/0:4/5520

CPU: 0 UID: 0 PID: 5520 Comm: kworker/0:4 Not tainted 6.15.0-syzkaller-10402-g4cb6c8af8591 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:443
 ib_get_eth_speed+0x15e/0x7b0 drivers/infiniband/core/verbs.c:1996
 rxe_query_port+0x93/0x3b0 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2111 [inline]
 ib_query_port+0x16d/0x830 drivers/infiniband/core/device.c:2143
 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:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 6144:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kvmalloc_node_noprof+0x314/0x600 mm/slub.c:5012
 alloc_netdev_mqs+0xa6/0x11e0 net/core/dev.c:11710
 rtnl_create_link+0x31f/0xd10 net/core/rtnetlink.c:3631
 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3813
 __rtnl_newlink net/core/rtnetlink.c:3940 [inline]
 rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:727
 __sys_sendto+0x3bd/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1035:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x18e/0x440 mm/slub.c:4841
 device_release+0x9c/0x1c0 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+0x22b/0x480 lib/kobject.c:737
 netdev_run_todo+0xd2e/0xea0 net/core/dev.c:11411
 default_device_exit_batch+0x81e/0x890 net/core/dev.c:12644
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x525/0x990 net/core/net_namespace.c:253
 cleanup_net+0x4c5/0x8a0 net/core/net_namespace.c:686
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 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 ffff888056352000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 744 bytes inside of
 freed 4096-byte region [ffff888056352000, ffff888056353000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x56350
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880336d0e41
anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801a44b500 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000000f5000000 ffff8880336d0e41
head: 04fff00000000040 ffff88801a44b500 0000000000000000 dead000000000001
head: 0000000000000000 0000000000040004 00000000f5000000 ffff8880336d0e41
head: 04fff00000000003 ffffea000158d401 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 5383, tgid 5383 (syz-executor), ts 326956863841, free_ts 323055098285
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1710
 prep_new_page mm/page_alloc.c:1718 [inline]
 get_page_from_freelist+0x21e0/0x22c0 mm/page_alloc.c:3680
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2618
 new_slab mm/slub.c:2672 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
 __slab_alloc mm/slub.c:3948 [inline]
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1376
 __addrconf_sysctl_register+0x398/0x530 net/ipv6/addrconf.c:7248
 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7296
 ipv6_add_dev+0xd46/0x1370 net/ipv6/addrconf.c:458
 addrconf_notify+0x794/0x1010 net/ipv6/addrconf.c:3654
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 register_netdevice+0x1608/0x1ae0 net/core/dev.c:11142
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:964 [inline]
 nsim_create+0xb19/0xef0 drivers/net/netdevsim/netdev.c:1032
 __nsim_dev_port_add+0x70a/0xb20 drivers/net/netdevsim/dev.c:1393
page last free pid 5357 tgid 5357 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1254 [inline]
 free_unref_folios+0xcc9/0x1550 mm/page_alloc.c:2774
 folios_put_refs+0x559/0x640 mm/swap.c:992
 free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:266
 __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:397 [inline]
 tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:496
 vms_clear_ptes+0x42c/0x540 mm/vma.c:1191
 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1233
 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1492
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1540
 __vm_munmap+0x23b/0x3d0 mm/vma.c:3014
 __do_sys_munmap mm/mmap.c:1084 [inline]
 __se_sys_munmap mm/mmap.c:1081 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056352180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056352200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888056352280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff888056352300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056352380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================