Extracting prog: 7m5.69851404s
Minimizing prog: 30m42.877967104s
Simplifying prog options: 14m32.365375126s
Extracting C: 5m16.440975307s
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:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfc, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4}, 0x810)

program did not crash
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:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfc, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4}, 0x810)

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=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfc, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4}, 0x810)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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, 0x810)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x4}, 0x810)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={0x0}, 0x1, 0x0, 0x0, 0x4}, 0x810)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfc, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4}, 0x810)

program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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=6m0s, {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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfc, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4}, 0x810)

program did not crash
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfc, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4}, 0x810)

program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfc, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4}, 0x810)

program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 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 CallComments:true 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, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000200)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfc, "", [{{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0x38}, 0x1, 0x0, 0x0, 0x4}, 0x810)

program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
validation run: crashed=true
reproducing took 1h5m53.209758511s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:443
Read of size 8 at addr ffff88807bf742e8 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 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>

Allocated by task 9816:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5657 [inline]
 __kvmalloc_node_noprof+0x5d5/0x920 mm/slub.c:7134
 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:11997
 rtnl_create_link+0x31f/0xcf0 net/core/rtnetlink.c:3648
 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3830
 __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
 rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 __sys_sendto+0x3bd/0x520 net/socket.c:2206
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 3457:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6668 [inline]
 kfree+0x1c0/0x660 mm/slub.c:6876
 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
 default_device_exit_batch+0x969/0x9e0 net/core/dev.c:13037
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x525/0x990 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

The buggy address belongs to the object at ffff88807bf74000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 744 bytes inside of
 freed 4096-byte region [ffff88807bf74000, ffff88807bf75000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bf70
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88802f3b8bc1
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813ffb0500 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000000f5000000 ffff88802f3b8bc1
head: 00fff00000000040 ffff88813ffb0500 0000000000000000 dead000000000001
head: 0000000000000000 0000000000040004 00000000f5000000 ffff88802f3b8bc1
head: 00fff00000000003 ffffea0001efdc01 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 5951, tgid 5951 (syz-executor), ts 101451330695, free_ts 101407802636
 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
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xf2b/0x1960 mm/slub.c:4656
 __slab_alloc+0x65/0x100 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_node_track_caller_noprof+0x5d4/0x820 mm/slub.c:5764
 kmemdup_noprof+0x2b/0x70 mm/util.c:138
 kmemdup_noprof include/linux/fortify-string.h:765 [inline]
 __addrconf_sysctl_register+0x9e/0x4c0 net/ipv6/addrconf.c:7305
 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7371
 ipv6_add_dev+0xd26/0x13a0 net/ipv6/addrconf.c:460
 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3650
 notifier_call_chain+0x19d/0x3a0 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+0x15bd/0x1a70 net/core/dev.c:11429
 veth_newlink+0x5d4/0xa60 drivers/net/veth.c:1885
page last free pid 5956 tgid 5956 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
 __slab_free+0x21b/0x2a0 mm/slub.c:6004
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
 __kernfs_new_node+0xdc/0x880 fs/kernfs/dir.c:637
 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:716
 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057
 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313
 sysfs_create_file_ns fs/sysfs/file.c:374 [inline]
 sysfs_create_file include/linux/sysfs.h:774 [inline]
 sysfs_create_files+0x154/0x320 fs/sysfs/file.c:384
 bond_enslave+0x200d/0x3ac0 drivers/net/bonding/bond_main.c:2146
 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963
 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3165
 rtnl_changelink net/core/rtnetlink.c:3776 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3935 [inline]
 rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958

Memory state around the buggy address:
 ffff88807bf74180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807bf74200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807bf74280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff88807bf74300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807bf74380: 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+0x5e/0x170 net/ethtool/ioctl.c:443
Read of size 8 at addr ffff88807bf742e8 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 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>

Allocated by task 9816:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5657 [inline]
 __kvmalloc_node_noprof+0x5d5/0x920 mm/slub.c:7134
 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:11997
 rtnl_create_link+0x31f/0xcf0 net/core/rtnetlink.c:3648
 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3830
 __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
 rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 __sys_sendto+0x3bd/0x520 net/socket.c:2206
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 3457:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6668 [inline]
 kfree+0x1c0/0x660 mm/slub.c:6876
 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
 default_device_exit_batch+0x969/0x9e0 net/core/dev.c:13037
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x525/0x990 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

The buggy address belongs to the object at ffff88807bf74000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 744 bytes inside of
 freed 4096-byte region [ffff88807bf74000, ffff88807bf75000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bf70
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88802f3b8bc1
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813ffb0500 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000000f5000000 ffff88802f3b8bc1
head: 00fff00000000040 ffff88813ffb0500 0000000000000000 dead000000000001
head: 0000000000000000 0000000000040004 00000000f5000000 ffff88802f3b8bc1
head: 00fff00000000003 ffffea0001efdc01 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 5951, tgid 5951 (syz-executor), ts 101451330695, free_ts 101407802636
 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
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xf2b/0x1960 mm/slub.c:4656
 __slab_alloc+0x65/0x100 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_node_track_caller_noprof+0x5d4/0x820 mm/slub.c:5764
 kmemdup_noprof+0x2b/0x70 mm/util.c:138
 kmemdup_noprof include/linux/fortify-string.h:765 [inline]
 __addrconf_sysctl_register+0x9e/0x4c0 net/ipv6/addrconf.c:7305
 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7371
 ipv6_add_dev+0xd26/0x13a0 net/ipv6/addrconf.c:460
 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3650
 notifier_call_chain+0x19d/0x3a0 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+0x15bd/0x1a70 net/core/dev.c:11429
 veth_newlink+0x5d4/0xa60 drivers/net/veth.c:1885
page last free pid 5956 tgid 5956 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
 __slab_free+0x21b/0x2a0 mm/slub.c:6004
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
 __kernfs_new_node+0xdc/0x880 fs/kernfs/dir.c:637
 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:716
 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057
 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313
 sysfs_create_file_ns fs/sysfs/file.c:374 [inline]
 sysfs_create_file include/linux/sysfs.h:774 [inline]
 sysfs_create_files+0x154/0x320 fs/sysfs/file.c:384
 bond_enslave+0x200d/0x3ac0 drivers/net/bonding/bond_main.c:2146
 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963
 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3165
 rtnl_changelink net/core/rtnetlink.c:3776 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3935 [inline]
 rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958

Memory state around the buggy address:
 ffff88807bf74180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807bf74200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807bf74280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff88807bf74300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807bf74380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================