================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x1bf/0x200 net/ethtool/ioctl.c:443 Read of size 8 at addr ffff8880576e62e8 by task kworker/0:9/5934 CPU: 0 UID: 0 PID: 5934 Comm: kworker/0:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events smc_ib_port_event_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 __ethtool_get_link_ksettings+0x1bf/0x200 net/ethtool/ioctl.c:443 __ethtool_get_link_ksettings+0x148/0x200 net/ethtool/ioctl.c:450 ib_get_eth_speed+0x122/0xb50 drivers/infiniband/core/verbs.c:1996 rxe_query_port+0x108/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:62 __ib_query_port drivers/infiniband/core/device.c:2148 [inline] ib_query_port drivers/infiniband/core/device.c:2180 [inline] ib_query_port+0x441/0x8a0 drivers/infiniband/core/device.c:2170 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline] smc_ib_port_event_work+0x12f/0xbf0 net/smc/smc_ib.c:388 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 12361: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5642 [inline] __kvmalloc_node_noprof+0x3a3/0x9c0 mm/slub.c:7100 alloc_netdev_mqs+0xd7/0x1550 net/core/dev.c:11900 rtnl_create_link+0xc08/0xf90 net/core/rtnetlink.c:3641 rtnl_newlink_create net/core/rtnetlink.c:3823 [inline] __rtnl_newlink net/core/rtnetlink.c:3950 [inline] rtnl_newlink+0xb69/0x2000 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6951 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x4a3/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 9051: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6837 device_release+0xa4/0x240 drivers/base/core.c:2565 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e7/0x5a0 lib/kobject.c:737 netdev_run_todo+0x7e9/0x1320 net/core/dev.c:11601 default_device_exit_batch+0x858/0xaf0 net/core/dev.c:12852 ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x363/0xab0 net/core/net_namespace.c:252 cleanup_net+0x41b/0x8b0 net/core/net_namespace.c:695 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 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 ffff8880576e6000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 744 bytes inside of freed 4096-byte region [ffff8880576e6000, ffff8880576e7000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x576e0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88807f392ec1 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffb0500 ffffea0001e96800 dead000000000002 raw: 0000000000000000 0000000000040004 00000000f5000000 ffff88807f392ec1 head: 00fff00000000040 ffff88813ffb0500 ffffea0001e96800 dead000000000002 head: 0000000000000000 0000000000040004 00000000f5000000 ffff88807f392ec1 head: 00fff00000000003 ffffea00015db801 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5183, tgid 5183 (udevd), ts 589522031044, free_ts 559203753557 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3055 [inline] allocate_slab mm/slub.c:3228 [inline] new_slab+0x24a/0x360 mm/slub.c:3282 ___slab_alloc+0xdae/0x1a60 mm/slub.c:4651 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4770 __slab_alloc_node mm/slub.c:4846 [inline] slab_alloc_node mm/slub.c:5268 [inline] __do_kmalloc_node mm/slub.c:5641 [inline] __kvmalloc_node_noprof+0x5aa/0x9c0 mm/slub.c:7100 seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x830/0x12d0 fs/seq_file.c:210 kernfs_fop_read_iter+0x46c/0x610 fs/kernfs/file.c:297 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x8bf/0xcf0 fs/read_write.c:572 ksys_read+0x12a/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 9062 tgid 9062 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4970 [inline] slab_alloc_node mm/slub.c:5280 [inline] kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5287 ext4_init_io_end+0x24/0x170 fs/ext4/page-io.c:310 ext4_do_writepages+0x9e7/0x3cf0 fs/ext4/inode.c:2872 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3025 do_writepages+0x27a/0x600 mm/page-writeback.c:2604 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1719 writeback_sb_inodes+0x60d/0xfa0 fs/fs-writeback.c:2015 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2086 wb_writeback+0x7f3/0xb70 fs/fs-writeback.c:2197 wb_check_old_data_flush fs/fs-writeback.c:2301 [inline] wb_do_writeback fs/fs-writeback.c:2354 [inline] wb_workfn+0x8ca/0xbe0 fs/fs-writeback.c:2382 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 Memory state around the buggy address: ffff8880576e6180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880576e6200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880576e6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880576e6300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880576e6380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================