Extracting prog: 4m42.541668034s
Minimizing prog: 36m44.983364735s
Simplifying prog options: 14m56.446321412s
Extracting C: 5m14.976194961s
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:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0xb0, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'rose0\x00'}}, {{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'xfrm0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'dummy0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0xb0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

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:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0xb0, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'rose0\x00'}}, {{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'xfrm0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'dummy0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0xb0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

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:4 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:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0xb0, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'rose0\x00'}}, {{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'xfrm0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'dummy0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0xb0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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, 0x4010)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000200)={0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x831}, 0x4010)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={0x0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0x10, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd}, 0x10}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0xb0, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'rose0\x00'}}, {{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'xfrm0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'dummy0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0xb0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

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:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0xb0, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'rose0\x00'}}, {{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'xfrm0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'dummy0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0xb0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

program did not crash
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0xb0, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'rose0\x00'}}, {{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'xfrm0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'dummy0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0xb0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

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:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0xb0, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'rose0\x00'}}, {{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'xfrm0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'dummy0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0xb0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

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:4 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, &(0x7f0000000200)={0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000040)={0xb0, 0x1403, 0x1, 0x70bd2c, 0x25dfdbfd, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'rose0\x00'}}, {{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'xfrm0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'dummy0\x00'}}, {{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan0\x00'}}]}, 0xb0}, 0x1, 0x0, 0x0, 0x831}, 0x4010)

program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings
validation run: crashed=true
reproducing took 1h9m18.033035895s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:444
Read of size 8 at addr ffff8880356d82f0 by task kworker/0:0/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events smc_ib_port_event_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:444
 ib_get_eth_speed+0x180/0x7f0 drivers/infiniband/core/verbs.c:2055
 rxe_query_port+0x93/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2120 [inline]
 ib_query_port+0x170/0x830 drivers/infiniband/core/device.c:2152
 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:3278 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3361
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3442
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 11363:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5292 [inline]
 __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6824
 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:12048
 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3667
 rtnl_newlink_create+0x277/0xb70 net/core/rtnetlink.c:3849
 __rtnl_newlink net/core/rtnetlink.c:3976 [inline]
 rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4091
 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6977
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:786 [inline]
 __sock_sendmsg net/socket.c:801 [inline]
 __sys_sendto+0x672/0x710 net/socket.c:2264
 __do_sys_sendto net/socket.c:2271 [inline]
 __se_sys_sendto net/socket.c:2267 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2267
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 3496:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/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:6242 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6557
 device_release+0xc4/0x1f0 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+0x228/0x560 lib/kobject.c:737
 netdev_run_todo+0xc75/0xde0 net/core/dev.c:11749
 default_device_exit_batch+0x986/0xa00 net/core/dev.c:13088
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x52b/0x940 net/core/net_namespace.c:252
 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3278 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3361
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3442
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 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 ffff8880356d8000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 752 bytes inside of
 freed 4096-byte region [ffff8880356d8000, ffff8880356d9000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x356d8
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 ffff88801b00e500 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b00e500 dead000000000100 dead000000000122
head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
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 5856, tgid 5856 (syz-executor), ts 74379181949, free_ts 74328355263
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x2418/0x24b0 mm/page_alloc.c:3926
 __alloc_frozen_pages_noprof+0x233/0x3d0 mm/page_alloc.c:5213
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7247
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __do_kmalloc_node mm/slub.c:5291 [inline]
 __kmalloc_noprof+0x474/0x760 mm/slub.c:5304
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379
 __addrconf_sysctl_register+0x331/0x4d0 net/ipv6/addrconf.c:7327
 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7375
 ipv6_add_dev+0xd26/0x13a0 net/ipv6/addrconf.c:459
 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3654
 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
 call_netdevice_notifiers net/core/dev.c:2302 [inline]
 register_netdevice+0x173a/0x1cf0 net/core/dev.c:11480
 register_netdev+0x40/0x60 net/core/dev.c:11558
 vti6_init_net+0x238/0x370 net/ipv6/ip6_vti.c:1158
page last free pid 5859 tgid 5859 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2944
 __slab_free+0x274/0x2c0 mm/slub.c:5605
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c: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+0x2bc/0x650 mm/slub.c:4905
 __proc_create+0x535/0xa60 fs/proc/generic.c:452
 proc_create_reg fs/proc/generic.c:578 [inline]
 proc_create_single_data+0xa5/0x1b0 fs/proc/generic.c:671
 psched_net_init+0x50/0x70 net/sched/sch_api.c:2454
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 setup_net+0x118/0x340 net/core/net_namespace.c:446
 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:581
 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x521/0x980 kernel/fork.c:3227
 __do_sys_unshare kernel/fork.c:3301 [inline]
 __se_sys_unshare kernel/fork.c:3299 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3299

Memory state around the buggy address:
 ffff8880356d8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880356d8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880356d8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8880356d8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880356d8380: 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:444
Read of size 8 at addr ffff8880356d82f0 by task kworker/0:0/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events smc_ib_port_event_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:444
 ib_get_eth_speed+0x180/0x7f0 drivers/infiniband/core/verbs.c:2055
 rxe_query_port+0x93/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2120 [inline]
 ib_query_port+0x170/0x830 drivers/infiniband/core/device.c:2152
 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:3278 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3361
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3442
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 11363:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5292 [inline]
 __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6824
 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:12048
 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3667
 rtnl_newlink_create+0x277/0xb70 net/core/rtnetlink.c:3849
 __rtnl_newlink net/core/rtnetlink.c:3976 [inline]
 rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4091
 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6977
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:786 [inline]
 __sock_sendmsg net/socket.c:801 [inline]
 __sys_sendto+0x672/0x710 net/socket.c:2264
 __do_sys_sendto net/socket.c:2271 [inline]
 __se_sys_sendto net/socket.c:2267 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2267
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 3496:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/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:6242 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6557
 device_release+0xc4/0x1f0 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+0x228/0x560 lib/kobject.c:737
 netdev_run_todo+0xc75/0xde0 net/core/dev.c:11749
 default_device_exit_batch+0x986/0xa00 net/core/dev.c:13088
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x52b/0x940 net/core/net_namespace.c:252
 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3278 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3361
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3442
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 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 ffff8880356d8000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 752 bytes inside of
 freed 4096-byte region [ffff8880356d8000, ffff8880356d9000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x356d8
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 ffff88801b00e500 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b00e500 dead000000000100 dead000000000122
head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
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 5856, tgid 5856 (syz-executor), ts 74379181949, free_ts 74328355263
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x2418/0x24b0 mm/page_alloc.c:3926
 __alloc_frozen_pages_noprof+0x233/0x3d0 mm/page_alloc.c:5213
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7247
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __do_kmalloc_node mm/slub.c:5291 [inline]
 __kmalloc_noprof+0x474/0x760 mm/slub.c:5304
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379
 __addrconf_sysctl_register+0x331/0x4d0 net/ipv6/addrconf.c:7327
 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7375
 ipv6_add_dev+0xd26/0x13a0 net/ipv6/addrconf.c:459
 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3654
 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
 call_netdevice_notifiers net/core/dev.c:2302 [inline]
 register_netdevice+0x173a/0x1cf0 net/core/dev.c:11480
 register_netdev+0x40/0x60 net/core/dev.c:11558
 vti6_init_net+0x238/0x370 net/ipv6/ip6_vti.c:1158
page last free pid 5859 tgid 5859 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2944
 __slab_free+0x274/0x2c0 mm/slub.c:5605
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c: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+0x2bc/0x650 mm/slub.c:4905
 __proc_create+0x535/0xa60 fs/proc/generic.c:452
 proc_create_reg fs/proc/generic.c:578 [inline]
 proc_create_single_data+0xa5/0x1b0 fs/proc/generic.c:671
 psched_net_init+0x50/0x70 net/sched/sch_api.c:2454
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 setup_net+0x118/0x340 net/core/net_namespace.c:446
 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:581
 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x521/0x980 kernel/fork.c:3227
 __do_sys_unshare kernel/fork.c:3301 [inline]
 __se_sys_unshare kernel/fork.c:3299 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3299

Memory state around the buggy address:
 ffff8880356d8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880356d8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880356d8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8880356d8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880356d8380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================