syzbot

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BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:442
Read of size 8 at addr ffff8880628f02e8 by task kworker/0:1/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.14.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events smc_ib_port_event_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:442
 ib_get_eth_speed+0x160/0x800 drivers/infiniband/core/verbs.c:1996
 rxe_query_port+0x95/0x3b0 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2095 [inline]
 ib_query_port+0x168/0x7d0 drivers/infiniband/core/device.c:2127
 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
 smc_ib_port_event_work+0x14e/0xa90 net/smc/smc_ib.c:388
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7ab/0x920 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5982:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_node_noprof+0x290/0x4d0 mm/slub.c:4300
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:662
 alloc_netdev_mqs+0xa4/0x1210 net/core/dev.c:11547
 rtnl_create_link+0x2f9/0xc90 net/core/rtnetlink.c:3605
 rtnl_newlink_create+0x210/0xa40 net/core/rtnetlink.c:3781
 __rtnl_newlink net/core/rtnetlink.c:3907 [inline]
 rtnl_newlink+0x17cc/0x1d30 net/core/rtnetlink.c:4022
 rtnetlink_rcv_msg+0x793/0xcf0 net/core/rtnetlink.c:6912
 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2533
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7f8/0x990 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1882
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:733
 __sys_sendto+0x363/0x4c0 net/socket.c:2187
 __do_sys_sendto net/socket.c:2194 [inline]
 __se_sys_sendto net/socket.c:2190 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2190
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 47:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x196/0x430 mm/slub.c:4757
 device_release+0x9b/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x231/0x480 lib/kobject.c:737
 netdev_run_todo+0xd9d/0xf30 net/core/dev.c:11248
 default_device_exit_batch+0x804/0x880 net/core/dev.c:12432
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x8af/0xd60 net/core/net_namespace.c:652
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7ab/0x920 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff8880628f0000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 744 bytes inside of
 freed 4096-byte region [ffff8880628f0000, ffff8880628f1000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x628f0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888048402501
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b04f500 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000000f5000000 ffff888048402501
head: 00fff00000000040 ffff88801b04f500 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000000f5000000 ffff888048402501
head: 00fff00000000003 ffffea00018a3c01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5982, tgid 5982 (syz-executor), ts 173981332381, free_ts 170160019072
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2587
 new_slab mm/slub.c:2640 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
 __slab_alloc+0x58/0xa0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_node_noprof+0x2ee/0x4d0 mm/slub.c:4300
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:662
 alloc_netdev_mqs+0xa4/0x1210 net/core/dev.c:11547
 rtnl_create_link+0x2f9/0xc90 net/core/rtnetlink.c:3605
 rtnl_newlink_create+0x210/0xa40 net/core/rtnetlink.c:3781
 __rtnl_newlink net/core/rtnetlink.c:3907 [inline]
 rtnl_newlink+0x17cc/0x1d30 net/core/rtnetlink.c:4022
 rtnetlink_rcv_msg+0x793/0xcf0 net/core/rtnetlink.c:6912
 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2533
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7f8/0x990 net/netlink/af_netlink.c:1338
page last free pid 5920 tgid 5920 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 vfree+0x1c3/0x360 mm/vmalloc.c:3383
 kcov_put kernel/kcov.c:439 [inline]
 kcov_close+0x28/0x50 kernel/kcov.c:535
 __fput+0x3eb/0x9f0 fs/file_table.c:464
 task_work_run+0x251/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2a/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 get_signal+0x168c/0x1720 kernel/signal.c:3036
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880628f0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880628f0200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880628f0280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff8880628f0300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880628f0380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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