==================================================================
BUG: KASAN: slab-out-of-bounds in iov_iter_revert lib/iov_iter.c:633 [inline]
BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x443/0x5a0 lib/iov_iter.c:611
Read of size 4 at addr ffff888028fc24f8 by task kworker/u8:18/17895

CPU: 0 UID: 0 PID: 17895 Comm: kworker/u8:18 Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #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+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 iov_iter_revert lib/iov_iter.c:633 [inline]
 iov_iter_revert+0x443/0x5a0 lib/iov_iter.c:611
 netfs_retry_write_stream fs/netfs/write_retry.c:44 [inline]
 netfs_retry_writes+0x166d/0x1a50 fs/netfs/write_retry.c:231
 netfs_collect_write_results fs/netfs/write_collect.c:352 [inline]
 netfs_write_collection_worker+0x23fd/0x3830 fs/netfs/write_collect.c:374
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c1/0xef0 kernel/workqueue.c:3400
 kthread+0x3a4/0x760 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 28299:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4318 [inline]
 __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4337
 kmemdup_noprof+0x29/0x60 mm/util.c:136
 kmemdup_noprof include/linux/fortify-string.h:765 [inline]
 sidtab_sid2str_get+0x17a/0x680 security/selinux/ss/sidtab.c:625
 sidtab_entry_to_string+0x33/0x110 security/selinux/ss/services.c:1295
 security_sid_to_context_core+0x35c/0x640 security/selinux/ss/services.c:1398
 selinux_inode_init_security+0x460/0x660 security/selinux/hooks.c:2946
 security_inode_init_security+0x1e5/0x390 security/security.c:1836
 shmem_symlink+0x134/0x780 mm/shmem.c:4112
 vfs_symlink fs/namei.c:4688 [inline]
 vfs_symlink+0x400/0x680 fs/namei.c:4672
 do_symlinkat+0x261/0x310 fs/namei.c:4714
 __do_sys_symlinkat fs/namei.c:4730 [inline]
 __se_sys_symlinkat fs/namei.c:4727 [inline]
 __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4727
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 28299:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2376 [inline]
 slab_free mm/slub.c:4633 [inline]
 kfree+0x2b6/0x4d0 mm/slub.c:4832
 security_inode_init_security+0x2c3/0x390 security/security.c:1855
 shmem_symlink+0x134/0x780 mm/shmem.c:4112
 vfs_symlink fs/namei.c:4688 [inline]
 vfs_symlink+0x400/0x680 fs/namei.c:4672
 do_symlinkat+0x261/0x310 fs/namei.c:4714
 __do_sys_symlinkat fs/namei.c:4730 [inline]
 __se_sys_symlinkat fs/namei.c:4727 [inline]
 __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4727
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888028fc24c0
 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 [ffff888028fc24c0, ffff888028fc24e0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28fc2
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b441780 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080400040 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 0x52800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP), pid 1756, tgid 1756 (kworker/u8:1), ts 7671480764, free_ts 7250051062
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x10c4/0x34c0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x223/0x24d0 mm/page_alloc.c:4740
 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2446 [inline]
 allocate_slab mm/slub.c:2610 [inline]
 new_slab+0x23c/0x330 mm/slub.c:2663
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3849
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3939
 __slab_alloc_node mm/slub.c:4014 [inline]
 slab_alloc_node mm/slub.c:4175 [inline]
 __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4344
 kmalloc_noprof include/linux/slab.h:902 [inline]
 slab_free_hook mm/slub.c:2328 [inline]
 slab_free mm/slub.c:4633 [inline]
 kmem_cache_free+0x148/0x4d0 mm/slub.c:4735
 file_free fs/file_table.c:76 [inline]
 __fput_deferred+0x2d5/0x370 fs/file_table.c:520
 fput_close+0x1a5/0x1e0 fs/file_table.c:582
 path_openat+0xf22/0x2d40 fs/namei.c:4013
 do_filp_open+0x20b/0x470 fs/namei.c:4031
 do_open_execat+0xf9/0x450 fs/exec.c:893
 alloc_bprm+0x2d/0xdd0 fs/exec.c:1517
 kernel_execve+0xb0/0x3b0 fs/exec.c:1989
page last free pid 972 tgid 972 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0x6d8/0xf40 mm/page_alloc.c:2660
 vfree+0x176/0x960 mm/vmalloc.c:3383
 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3303
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c1/0xef0 kernel/workqueue.c:3400
 kthread+0x3a4/0x760 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 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:
 ffff888028fc2380: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888028fc2400: 00 00 00 00 fc fc fc fc 00 00 00 fc fc fc fc fc
>ffff888028fc2480: 00 00 04 fc fc fc fc fc fa fb fb fb fc fc fc fc
                                                                ^
 ffff888028fc2500: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888028fc2580: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
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