==================================================================
BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x1c1/0x5a0 lib/iov_iter.c:633
Read of size 4 at addr ffff88802ecd34f8 by task kworker/u8:14/8914

CPU: 1 UID: 0 PID: 8914 Comm: kworker/u8:14 Not tainted 6.15.0-rc1-syzkaller-00246-g900241a5cc15 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound netfs_write_collection_worker
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
 iov_iter_revert+0x1c1/0x5a0 lib/iov_iter.c:633
 netfs_retry_write_stream fs/netfs/write_retry.c:44 [inline]
 netfs_retry_writes+0x17f2/0x19d0 fs/netfs/write_retry.c:231
 netfs_collect_write_results fs/netfs/write_collect.c:352 [inline]
 netfs_write_collection_worker+0x2fc0/0x3bf0 fs/netfs/write_collect.c:374
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 1:
 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+0x9d/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4331 [inline]
 __kmalloc_node_track_caller_noprof+0x295/0x4d0 mm/slub.c:4350
 __do_krealloc mm/slub.c:4908 [inline]
 krealloc_noprof+0x10f/0x300 mm/slub.c:4961
 krealloc_array_noprof include/linux/slab.h:979 [inline]
 add_sysfs_param+0x165/0x840 kernel/params.c:662
 kernel_add_sysfs_param+0xb4/0x130 kernel/params.c:814
 param_sysfs_builtin+0x1dd/0x2a0 kernel/params.c:853
 param_sysfs_builtin_init+0x31/0x40 kernel/params.c:987
 do_one_initcall+0x24a/0x940 init/main.c:1257
 do_initcall_level+0x157/0x210 init/main.c:1319
 do_initcalls+0x71/0xd0 init/main.c:1335
 kernel_init_freeable+0x432/0x5d0 init/main.c:1567
 kernel_init+0x1d/0x2b0 init/main.c:1457
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff88802ecd34e0
 which belongs to the cache kmalloc-16 of size 16
The buggy address is located 8 bytes to the right of
 allocated 16-byte region [ffff88802ecd34e0, ffff88802ecd34f0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ecd3
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b041640 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000800080 00000000f5000000 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 36, tgid 36 (kworker/u8:2), ts 19181812861, free_ts 19145257811
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1717
 prep_new_page mm/page_alloc.c:1725 [inline]
 get_page_from_freelist+0x351d/0x36b0 mm/page_alloc.c:3652
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2459 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2623
 new_slab mm/slub.c:2676 [inline]
 ___slab_alloc+0xc3b/0x1500 mm/slub.c:3862
 __slab_alloc+0x58/0xa0 mm/slub.c:3952
 __slab_alloc_node mm/slub.c:4027 [inline]
 slab_alloc_node mm/slub.c:4188 [inline]
 __do_kmalloc_node mm/slub.c:4330 [inline]
 __kmalloc_noprof+0x2ea/0x4d0 mm/slub.c:4343
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 lsm_blob_alloc security/security.c:684 [inline]
 lsm_task_alloc security/security.c:771 [inline]
 security_task_alloc+0x4a/0x340 security/security.c:3160
 copy_process+0x1605/0x3d10 kernel/fork.c:2411
 kernel_clone+0x227/0x880 kernel/fork.c:2844
 user_mode_thread+0x148/0x1c0 kernel/fork.c:2922
 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
page last free pid 1206 tgid 1206 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0xddf/0x10a0 mm/page_alloc.c:2680
 vfree+0x1c3/0x360 mm/vmalloc.c:3383
 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3303
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88802ecd3380: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc
 ffff88802ecd3400: 00 00 fc fc 00 00 fc fc fa fb fc fc 00 04 fc fc
>ffff88802ecd3480: 00 00 fc fc 00 04 fc fc 00 00 fc fc 00 00 fc fc
                                                                ^
 ffff88802ecd3500: 00 00 fc fc 00 02 fc fc 00 02 fc fc 00 00 fc fc
 ffff88802ecd3580: 00 03 fc fc 00 00 fc fc 00 00 fc fc fa fb fc fc
==================================================================