Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings ================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:442 Read of size 8 at addr ffff8880673be308 by task kworker/0:1/9 CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.12.0-rc2-syzkaller-g615b94746a54-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __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+0x76/0x260 drivers/infiniband/sw/rxe/rxe_verbs.c:55 __ib_query_port drivers/infiniband/core/device.c:2105 [inline] ib_query_port+0x208/0x870 drivers/infiniband/core/device.c:2147 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline] smc_ib_port_event_work+0x14e/0xa50 net/smc/smc_ib.c:388 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 5967: 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:257 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_node_noprof+0x22a/0x440 mm/slub.c:4270 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:658 alloc_netdev_mqs+0x9b/0x1000 net/core/dev.c:11097 rtnl_create_link+0x2f9/0xc20 net/core/rtnetlink.c:3374 rtnl_newlink_create net/core/rtnetlink.c:3500 [inline] __rtnl_newlink net/core/rtnetlink.c:3730 [inline] rtnl_newlink+0x1423/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 __sys_sendto+0x39b/0x4f0 net/socket.c:2209 __do_sys_sendto net/socket.c:2221 [inline] __se_sys_sendto net/socket.c:2217 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2217 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 11: 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:579 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:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x1a0/0x440 mm/slub.c:4727 device_release+0x99/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22f/0x480 lib/kobject.c:737 netdev_run_todo+0xe79/0x1000 net/core/dev.c:10816 default_device_exit_batch+0xa24/0xaa0 net/core/dev.c:11949 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x89d/0xcc0 net/core/net_namespace.c:626 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff8880673be000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 776 bytes inside of freed 4096-byte region [ffff8880673be000, ffff8880673bf000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x673b8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888031406a41 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801ac4f500 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000001f5000000 ffff888031406a41 head: 00fff00000000040 ffff88801ac4f500 dead000000000122 0000000000000000 head: 0000000000000000 0000000000040004 00000001f5000000 ffff888031406a41 head: 00fff00000000003 ffffea00019cee01 ffffffffffffffff 0000000000000000 head: 0000000700000008 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5982, tgid 5982 (syz-executor), ts 102124010087, free_ts 96435310364 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x120 mm/slub.c:2412 allocate_slab+0x5a/0x2f0 mm/slub.c:2578 new_slab mm/slub.c:2631 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818 __slab_alloc+0x58/0xa0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4290 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:359 [inline] ipv6_add_dev+0x570/0x1220 net/ipv6/addrconf.c:409 addrconf_notify+0x6a7/0x1020 net/ipv6/addrconf.c:3655 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline] call_netdevice_notifiers net/core/dev.c:2048 [inline] register_netdevice+0x167f/0x1b00 net/core/dev.c:10524 veth_newlink+0x855/0xce0 drivers/net/veth.c:1861 rtnl_newlink_create net/core/rtnetlink.c:3510 [inline] __rtnl_newlink net/core/rtnetlink.c:3730 [inline] rtnl_newlink+0x1591/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646 page last free pid 5869 tgid 5869 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_folios+0xf12/0x18d0 mm/page_alloc.c:2686 folios_put_refs+0x76c/0x860 mm/swap.c:1007 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:332 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 vms_clear_ptes+0x437/0x530 mm/vma.c:1096 vms_complete_munmap_vmas+0x208/0x910 mm/vma.c:1140 do_vmi_align_munmap+0x613/0x730 mm/vma.c:1349 do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1397 __vm_munmap+0x24c/0x480 mm/mmap.c:1600 __do_sys_munmap mm/mmap.c:1617 [inline] __se_sys_munmap mm/mmap.c:1614 [inline] __x64_sys_munmap+0x68/0x80 mm/mmap.c:1614 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 Memory state around the buggy address: ffff8880673be200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880673be280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880673be300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880673be380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880673be400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Tested on: commit: 615b9474 RDMA/hns: Disassociate mmap pages for all uct.. git tree: https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git for-next console output: https://syzkaller.appspot.com/x/log.txt?x=131b1707980000 kernel config: https://syzkaller.appspot.com/x/.config?x=7cd9e7e4a8a0a15b dashboard link: https://syzkaller.appspot.com/bug?extid=5fe14f2ff4ccbace9a26 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 patch: https://syzkaller.appspot.com/x/patch.diff?x=17698f9f980000