Extracting prog: 4m5.467187444s Minimizing prog: 31m59.97787759s Simplifying prog options: 15m37.621136168s Extracting C: 5m53.672395004s 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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={&(0x7f0000000380)={0x60, 0x1403, 0x13, 0x0, 0x0, "", [{{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'pimreg\x00'}}, {{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x60}}, 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: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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={&(0x7f0000000380)={0x60, 0x1403, 0x13, 0x0, 0x0, "", [{{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'pimreg\x00'}}, {{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x60}}, 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=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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={&(0x7f0000000380)={0x60, 0x1403, 0x13, 0x0, 0x0, "", [{{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'pimreg\x00'}}, {{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x60}}, 0x0) 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, 0x0) 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, &(0x7f0000000280)={0x0, 0x0, 0x0}, 0x0) 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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={0x0}}, 0x0) 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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={&(0x7f0000000380)={0x60, 0x1403, 0x13, 0x0, 0x0, "", [{{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'pimreg\x00'}}, {{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x60}}, 0x0) 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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={&(0x7f0000000380)={0x60, 0x1403, 0x13, 0x0, 0x0, "", [{{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'pimreg\x00'}}, {{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x60}}, 0x0) 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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={&(0x7f0000000380)={0x60, 0x1403, 0x13, 0x0, 0x0, "", [{{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'pimreg\x00'}}, {{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x60}}, 0x0) 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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={&(0x7f0000000380)={0x60, 0x1403, 0x13, 0x0, 0x0, "", [{{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'pimreg\x00'}}, {{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x60}}, 0x0) 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, &(0x7f0000000280)={0x0, 0x0, &(0x7f0000000240)={&(0x7f0000000380)={0x60, 0x1403, 0x13, 0x0, 0x0, "", [{{0x9, 0x2, 'syz0\x00'}, {0x8, 0x41, 'siw\x00'}, {0x14, 0x33, 'pimreg\x00'}}, {{0x9, 0x2, 'syz2\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'ipvlan1\x00'}}]}, 0x60}}, 0x0) program crashed: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings validation run: crashed=true reproducing took 1h6m34.039713224s repro crashed as (corrupted=false): ================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x190/0x1c0 net/ethtool/ioctl.c:444 Read of size 8 at addr ffff88807c8d22f0 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 03/18/2026 Workqueue: events smc_ib_port_event_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 __ethtool_get_link_ksettings+0x190/0x1c0 net/ethtool/ioctl.c:444 __ethtool_get_link_ksettings+0x144/0x1c0 net/ethtool/ioctl.c:451 ib_get_eth_speed+0x13a/0xb40 drivers/infiniband/core/verbs.c:2055 rxe_query_port+0x12a/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:62 __ib_query_port drivers/infiniband/core/device.c:2121 [inline] ib_query_port drivers/infiniband/core/device.c:2153 [inline] ib_query_port+0x445/0x8b0 drivers/infiniband/core/device.c:2143 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline] smc_ib_port_event_work+0x14c/0xbd0 net/smc/smc_ib.c:388 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 10585: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kvmalloc_node_noprof+0x360/0xa00 mm/slub.c:6828 alloc_netdev_mqs+0xd7/0x14f0 net/core/dev.c:12076 rtnl_create_link+0xc13/0xf80 net/core/rtnetlink.c:3670 rtnl_newlink_create net/core/rtnetlink.c:3852 [inline] __rtnl_newlink net/core/rtnetlink.c:3993 [inline] rtnl_newlink+0x13bd/0x2380 net/core/rtnetlink.c:4108 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6994 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x468/0x4b0 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 48: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/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:6246 [inline] kfree+0x223/0x6c0 mm/slub.c:6561 device_release+0xd2/0x270 drivers/base/core.c:2566 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1f7/0x640 lib/kobject.c:737 netdev_run_todo+0x817/0x12c0 net/core/dev.c:11777 default_device_exit_batch+0x94b/0xc60 net/core/dev.c:13120 ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x363/0xab0 net/core/net_namespace.c:252 cleanup_net+0x499/0x920 net/core/net_namespace.c:702 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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 ffff88807c8d2000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 752 bytes inside of freed 4096-byte region [ffff88807c8d2000, ffff88807c8d3000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c8d0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88807c8d1011 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fea4500 dead000000000100 dead000000000122 raw: 0000000000000000 0000200000040004 00000000f5000000 ffff88807c8d1011 head: 00fff00000000040 ffff88813fea4500 dead000000000100 dead000000000122 head: 0000000000000000 0000200000040004 00000000f5000000 ffff88807c8d1011 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 5962, tgid 5962 (syz-executor), ts 122346605371, free_ts 52825419439 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7251 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5410 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:362 [inline] ipv6_add_dev+0x670/0x1520 net/ipv6/addrconf.c:413 addrconf_notify+0x5db/0x1ba0 net/ipv6/addrconf.c:3662 notifier_call_chain+0x99/0x400 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] register_netdevice+0x16e6/0x2210 net/core/dev.c:11508 register_netdev+0x34/0x50 net/core/dev.c:11586 sit_init_net+0x2c0/0x5e0 net/ipv6/sit.c:1860 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x118/0x3a0 net/core/net_namespace.c:446 page last free pid 5706 tgid 5706 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 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+0x241/0x6e0 mm/slub.c:4905 vm_area_dup+0x27/0x8e0 mm/vma_init.c:123 __split_vma+0x18c/0xd90 mm/vma.c:516 vms_gather_munmap_vmas+0x1d2/0x1720 mm/vma.c:1427 __mmap_setup mm/vma.c:2439 [inline] __mmap_region+0x4aa/0x2da0 mm/vma.c:2753 mmap_region+0x35d/0x620 mm/vma.c:2856 do_mmap+0xc63/0x12f0 mm/mmap.c:560 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581 ksys_mmap_pgoff+0x3cb/0x610 mm/mmap.c:606 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807c8d2180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c8d2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807c8d2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c8d2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c8d2380: 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+0x190/0x1c0 net/ethtool/ioctl.c:444 Read of size 8 at addr ffff88807c8d22f0 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 03/18/2026 Workqueue: events smc_ib_port_event_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 __ethtool_get_link_ksettings+0x190/0x1c0 net/ethtool/ioctl.c:444 __ethtool_get_link_ksettings+0x144/0x1c0 net/ethtool/ioctl.c:451 ib_get_eth_speed+0x13a/0xb40 drivers/infiniband/core/verbs.c:2055 rxe_query_port+0x12a/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:62 __ib_query_port drivers/infiniband/core/device.c:2121 [inline] ib_query_port drivers/infiniband/core/device.c:2153 [inline] ib_query_port+0x445/0x8b0 drivers/infiniband/core/device.c:2143 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline] smc_ib_port_event_work+0x14c/0xbd0 net/smc/smc_ib.c:388 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 10585: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kvmalloc_node_noprof+0x360/0xa00 mm/slub.c:6828 alloc_netdev_mqs+0xd7/0x14f0 net/core/dev.c:12076 rtnl_create_link+0xc13/0xf80 net/core/rtnetlink.c:3670 rtnl_newlink_create net/core/rtnetlink.c:3852 [inline] __rtnl_newlink net/core/rtnetlink.c:3993 [inline] rtnl_newlink+0x13bd/0x2380 net/core/rtnetlink.c:4108 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6994 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x468/0x4b0 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 48: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/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:6246 [inline] kfree+0x223/0x6c0 mm/slub.c:6561 device_release+0xd2/0x270 drivers/base/core.c:2566 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1f7/0x640 lib/kobject.c:737 netdev_run_todo+0x817/0x12c0 net/core/dev.c:11777 default_device_exit_batch+0x94b/0xc60 net/core/dev.c:13120 ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x363/0xab0 net/core/net_namespace.c:252 cleanup_net+0x499/0x920 net/core/net_namespace.c:702 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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 ffff88807c8d2000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 752 bytes inside of freed 4096-byte region [ffff88807c8d2000, ffff88807c8d3000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c8d0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88807c8d1011 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fea4500 dead000000000100 dead000000000122 raw: 0000000000000000 0000200000040004 00000000f5000000 ffff88807c8d1011 head: 00fff00000000040 ffff88813fea4500 dead000000000100 dead000000000122 head: 0000000000000000 0000200000040004 00000000f5000000 ffff88807c8d1011 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 5962, tgid 5962 (syz-executor), ts 122346605371, free_ts 52825419439 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7251 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5410 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:362 [inline] ipv6_add_dev+0x670/0x1520 net/ipv6/addrconf.c:413 addrconf_notify+0x5db/0x1ba0 net/ipv6/addrconf.c:3662 notifier_call_chain+0x99/0x400 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] register_netdevice+0x16e6/0x2210 net/core/dev.c:11508 register_netdev+0x34/0x50 net/core/dev.c:11586 sit_init_net+0x2c0/0x5e0 net/ipv6/sit.c:1860 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x118/0x3a0 net/core/net_namespace.c:446 page last free pid 5706 tgid 5706 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 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+0x241/0x6e0 mm/slub.c:4905 vm_area_dup+0x27/0x8e0 mm/vma_init.c:123 __split_vma+0x18c/0xd90 mm/vma.c:516 vms_gather_munmap_vmas+0x1d2/0x1720 mm/vma.c:1427 __mmap_setup mm/vma.c:2439 [inline] __mmap_region+0x4aa/0x2da0 mm/vma.c:2753 mmap_region+0x35d/0x620 mm/vma.c:2856 do_mmap+0xc63/0x12f0 mm/mmap.c:560 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581 ksys_mmap_pgoff+0x3cb/0x610 mm/mmap.c:606 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807c8d2180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c8d2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807c8d2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c8d2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c8d2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================