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BUG: KASAN: use-after-free in genlmsg_multicast_netns include/net/genetlink.h:336 [inline]
BUG: KASAN: use-after-free in devlink_param_notify+0x131/0x1c0 net/devlink/leftover.c:5410
Read of size 8 at addr ffff88807c2e9e90 by task syz-executor/10031

CPU: 0 PID: 10031 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 genlmsg_multicast_netns include/net/genetlink.h:336 [inline]
 devlink_param_notify+0x131/0x1c0 net/devlink/leftover.c:5410
 devlink_notify_unregister net/devlink/leftover.c:9728 [inline]
 devlink_unregister+0x117/0x540 net/devlink/leftover.c:9784
 nsim_drv_remove+0x4c/0x170 drivers/net/netdevsim/dev.c:1677
 device_remove drivers/base/dd.c:547 [inline]
 __device_release_driver drivers/base/dd.c:1279 [inline]
 device_release_driver_internal+0x47d/0x7c0 drivers/base/dd.c:1305
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3900
 device_unregister+0x1c/0xc0 drivers/base/core.c:3943
 nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline]
 del_device_store+0x2b2/0x370 drivers/net/netdevsim/bus.c:219
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2271 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa102d5ed8e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007ffd7178b218 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555580d80500 RCX: 00007fa102d5ed8e
RDX: 0000000000000001 RSI: 00007ffd7178b2a0 RDI: 0000000000000005
RBP: 00007fa102e36174 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffd7178b2a0 R14: 00007ffd7178bae0 R15: 0000000000000003
 </TASK>

Allocated by task 7232:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 slab_alloc mm/slub.c:3367 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
 kmem_cache_alloc+0x18b/0x2f0 mm/slub.c:3383
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 net_alloc net/core/net_namespace.c:423 [inline]
 copy_net_ns+0x13c/0x5b0 net/core/net_namespace.c:495
 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x4f6/0x8e0 kernel/fork.c:3285
 __do_sys_unshare kernel/fork.c:3359 [inline]
 __se_sys_unshare kernel/fork.c:3357 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3357
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486
 insert_work+0x54/0x3c0 kernel/workqueue.c:1361
 __queue_work+0xae2/0xee0 kernel/workqueue.c:1520
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1747 [inline]
 __run_timers+0x598/0x810 kernel/time/timer.c:2023
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x667/0xa30 kernel/smpboot.c:164
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff88807c2e9c40
 which belongs to the cache net_namespace of size 6976
The buggy address is located 592 bytes inside of
 6976-byte region [ffff88807c2e9c40, ffff88807c2eb780)

The buggy address belongs to the physical page:
page:ffffea0001f0ba00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807c2eb880 pfn:0x7c2e8
head:ffffea0001f0ba00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88802936c081
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0000944800 dead000000000002 ffff888140009500
raw: ffff88807c2eb880 0000000080040000 00000001ffffffff ffff88802936c081
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 4285, tgid 4285 (syz-executor), ts 78801871618, free_ts 67763740074
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560
 prep_new_page mm/page_alloc.c:2567 [inline]
 get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358
 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658
 alloc_slab_page+0x5d/0x180 mm/slub.c:1799
 allocate_slab mm/slub.c:1944 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:1997
 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154
 __slab_alloc mm/slub.c:3240 [inline]
 slab_alloc_node mm/slub.c:3325 [inline]
 slab_alloc mm/slub.c:3367 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
 kmem_cache_alloc+0x111/0x2f0 mm/slub.c:3383
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 net_alloc net/core/net_namespace.c:423 [inline]
 copy_net_ns+0x13c/0x5b0 net/core/net_namespace.c:495
 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x4f6/0x8e0 kernel/fork.c:3285
 __do_sys_unshare kernel/fork.c:3359 [inline]
 __se_sys_unshare kernel/fork.c:3357 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3357
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1487 [inline]
 free_pcp_prepare mm/page_alloc.c:1537 [inline]
 free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414
 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509
 free_slab mm/slub.c:2036 [inline]
 discard_slab mm/slub.c:2042 [inline]
 __unfreeze_partials+0x188/0x1e0 mm/slub.c:2591
 put_cpu_partial+0x17c/0x250 mm/slub.c:2667
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 slab_alloc mm/slub.c:3367 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
 kmem_cache_alloc+0x18b/0x2f0 mm/slub.c:3383
 vm_area_alloc+0x20/0xe0 kernel/fork.c:460
 __mmap_region mm/mmap.c:2753 [inline]
 mmap_region+0xcbc/0x1c50 mm/mmap.c:2916
 do_mmap+0x9ce/0x10d0 mm/mmap.c:1436
 vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:520
 ksys_mmap_pgoff+0x4bf/0x720 mm/mmap.c:1482
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff88807c2e9d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807c2e9e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807c2e9e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88807c2e9f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807c2e9f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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