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BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x1c1/0x590 lib/iov_iter.c:631
Read of size 4 at addr ffff88802cc42838 by task kworker/u8:8/5321

CPU: 0 UID: 0 PID: 5321 Comm: kworker/u8:8 Not tainted 6.11.0-syzkaller-07341-gbaeb9a7d8b60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: events_unbound netfs_write_collection_worker
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 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
 iov_iter_revert+0x1c1/0x590 lib/iov_iter.c:631
 netfs_retry_write_stream fs/netfs/write_collect.c:181 [inline]
 netfs_retry_writes fs/netfs/write_collect.c:361 [inline]
 netfs_collect_write_results fs/netfs/write_collect.c:529 [inline]
 netfs_write_collection_worker+0x3ac1/0x4950 fs/netfs/write_collect.c:551
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5563:
 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]
 __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4296
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1004 [inline]
 ref_tracker_alloc+0x14b/0x490 lib/ref_tracker.c:203
 __netdev_tracker_alloc include/linux/netdevice.h:4050 [inline]
 netdev_hold include/linux/netdevice.h:4079 [inline]
 netdev_queue_add_kobject net/core/net-sysfs.c:1786 [inline]
 netdev_queue_update_kobjects+0x181/0x550 net/core/net-sysfs.c:1841
 register_queue_kobjects net/core/net-sysfs.c:1903 [inline]
 netdev_register_kobject+0x265/0x310 net/core/net-sysfs.c:2143
 register_netdevice+0x12c5/0x1b00 net/core/dev.c:10487
 __ip_tunnel_create+0x2b4/0x380 net/ipv4/ip_tunnel.c:267
 ip_tunnel_init_net+0x21c/0x720 net/ipv4/ip_tunnel.c:1160
 vti_init_net+0x2e/0xf0 net/ipv4/ip_vti.c:517
 ops_init+0x320/0x590 net/core/net_namespace.c:139
 setup_net+0x287/0x9e0 net/core/net_namespace.c:356
 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:494
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x619/0xc10 kernel/fork.c:3308
 __do_sys_unshare kernel/fork.c:3379 [inline]
 __se_sys_unshare kernel/fork.c:3377 [inline]
 __x64_sys_unshare+0x38/0x40 kernel/fork.c:3377
 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

The buggy address belongs to the object at ffff88802cc42800
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes to the right of
 allocated 32-byte region [ffff88802cc42800, ffff88802cc42820)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2cc42
ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000000 ffff88801ac41780 ffffea00009f5640 dead000000000003
raw: 0000000000000000 0000000000400040 00000001fdffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP), pid 4190, tgid 4190 (kworker/u8:1), ts 16905710898, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1500
 prep_new_page mm/page_alloc.c:1508 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3446
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4702
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263
 alloc_slab_page+0x6a/0x130 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 slab_free_hook mm/slub.c:2295 [inline]
 slab_free mm/slub.c:4580 [inline]
 kmem_cache_free+0x178/0x420 mm/slub.c:4682
 __exit_signal kernel/exit.c:212 [inline]
 release_task+0x111e/0x1830 kernel/exit.c:258
 exit_notify kernel/exit.c:776 [inline]
 do_exit+0x1b01/0x27f0 kernel/exit.c:902
 call_usermodehelper_exec_async+0x37a/0x380 kernel/umh.c:123
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802cc42700: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff88802cc42780: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
>ffff88802cc42800: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
                                        ^
 ffff88802cc42880: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff88802cc42900: 00 00 04 fc fc fc fc fc 00 00 04 fc fc fc fc fc
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