================================================================== BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x1da/0x5f0 lib/iov_iter.c:633 Read of size 4 at addr ffff8880323740b8 by task kworker/u8:9/6288 CPU: 0 UID: 0 PID: 6288 Comm: kworker/u8:9 Not tainted 6.15.0-rc7-syzkaller-00112-geccf6f2f6ab9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound netfs_write_collection_worker Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xb4/0x290 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 iov_iter_revert+0x1da/0x5f0 lib/iov_iter.c:633 netfs_retry_write_stream fs/netfs/write_retry.c:44 [inline] netfs_retry_writes+0x1645/0x1840 fs/netfs/write_retry.c:231 netfs_collect_write_results fs/netfs/write_collect.c:352 [inline] netfs_write_collection_worker+0x2007/0x2bd0 fs/netfs/write_collect.c:374 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 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 Allocated by task 5805: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:905 [inline] add_stack_record_to_list mm/page_owner.c:172 [inline] inc_stack_record_count mm/page_owner.c:214 [inline] __set_page_owner+0x25c/0x4a0 mm/page_owner.c:333 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2392 pagetable_alloc_noprof include/linux/mm.h:3002 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:70 [inline] pte_alloc_one+0x1e/0x160 arch/x86/mm/pgtable.c:17 do_fault_around mm/memory.c:5470 [inline] do_read_fault mm/memory.c:5509 [inline] do_fault mm/memory.c:5652 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x27e8/0x5380 mm/memory.c:6140 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6309 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 The buggy address belongs to the object at ffff8880323740a0 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 [ffff8880323740a0, ffff8880323740b0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32374 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801a041640 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080800080 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 1, tgid 1 (swapper/0), ts 25271822032, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2618 new_slab mm/slub.c:2672 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858 __slab_alloc mm/slub.c:3948 [inline] __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __do_kmalloc_node mm/slub.c:4326 [inline] __kmalloc_node_track_caller_noprof+0x2f8/0x4e0 mm/slub.c:4346 __kmemdup_nul mm/util.c:63 [inline] kstrdup+0x42/0x100 mm/util.c:83 kobject_set_name_vargs+0x61/0x110 lib/kobject.c:274 kobject_add_varg lib/kobject.c:368 [inline] kobject_init_and_add+0xdd/0x190 lib/kobject.c:457 lookup_or_create_module_kobject+0xe3/0x170 kernel/params.c:779 kernel_add_sysfs_param+0x1f/0x130 kernel/params.c:802 param_sysfs_builtin+0x1de/0x290 kernel/params.c:850 param_sysfs_builtin_init+0x32/0x40 kernel/params.c:986 do_one_initcall+0x233/0x820 init/main.c:1257 do_initcall_level+0x137/0x1f0 init/main.c:1319 page_owner free stack trace missing Memory state around the buggy address: ffff888032373f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888032374000: 00 04 fc fc 00 04 fc fc 00 00 fc fc 00 00 fc fc >ffff888032374080: 00 00 fc fc 00 00 fc fc 00 00 fc fc fa fb fc fc ^ ffff888032374100: 00 00 fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc ffff888032374180: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ==================================================================