================================================================== BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x1da/0x5f0 lib/iov_iter.c:633 Read of size 4 at addr ffff88802afd9b78 by task kworker/u8:15/9525 CPU: 1 UID: 0 PID: 9525 Comm: kworker/u8:15 Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 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+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/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 16859: 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] slab_free_hook mm/slub.c:2332 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x169/0x3f0 mm/slub.c:4744 p9_req_put+0x19b/0x1f0 net/9p/client.c:409 p9_client_write+0x3f5/0x740 net/9p/client.c:1674 v9fs_issue_write+0xdd/0x180 fs/9p/vfs_addr.c:59 netfs_do_issue_write fs/netfs/write_issue.c:239 [inline] netfs_issue_write fs/netfs/write_issue.c:269 [inline] netfs_end_issue_write+0x17d/0x410 fs/netfs/write_issue.c:541 netfs_unbuffered_write+0x585/0x600 fs/netfs/write_issue.c:733 netfs_unbuffered_write_iter_locked+0x443/0x990 fs/netfs/direct_write.c:100 netfs_unbuffered_write_iter+0x4c4/0x660 fs/netfs/direct_write.c:195 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x548/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 23: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x193/0x440 mm/slub.c:4841 slab_free_after_rcu_debug+0x62/0x290 mm/slub.c:4679 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2824 handle_softirqs+0x283/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164 kthread+0x70e/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 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3082 [inline] call_rcu+0x142/0x990 kernel/rcu/tree.c:3202 slab_free_hook mm/slub.c:2344 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x301/0x3f0 mm/slub.c:4744 p9_req_put+0x19b/0x1f0 net/9p/client.c:409 p9_client_write+0x3f5/0x740 net/9p/client.c:1674 v9fs_issue_write+0xdd/0x180 fs/9p/vfs_addr.c:59 netfs_do_issue_write fs/netfs/write_issue.c:239 [inline] netfs_issue_write fs/netfs/write_issue.c:269 [inline] netfs_end_issue_write+0x17d/0x410 fs/netfs/write_issue.c:541 netfs_unbuffered_write+0x585/0x600 fs/netfs/write_issue.c:733 netfs_unbuffered_write_iter_locked+0x443/0x990 fs/netfs/direct_write.c:100 netfs_unbuffered_write_iter+0x4c4/0x660 fs/netfs/direct_write.c:195 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x548/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802afd9b40 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 [ffff88802afd9b40, ffff88802afd9b60) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2afd9 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801a041780 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000400040 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 6678, tgid 6678 (kworker/u8:12), ts 190401559982, free_ts 168664449202 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970 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] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:905 [inline] slab_free_hook mm/slub.c:2332 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x169/0x3f0 mm/slub.c:4744 io_req_caches_free+0xa4/0x110 io_uring/io_uring.c:2722 io_ring_exit_work+0x3d8/0x880 io_uring/io_uring.c:2922 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/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 page last free pid 7099 tgid 7089 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2725 __slab_free+0x326/0x400 mm/slub.c:4553 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_krealloc+0x1f/0x140 mm/kasan/common.c:443 kasan_krealloc include/linux/kasan.h:280 [inline] __do_krealloc mm/slub.c:4900 [inline] krealloc_noprof+0x1b6/0x330 mm/slub.c:4957 copy_array+0x63/0xf0 kernel/bpf/verifier.c:1380 copy_stack_state kernel/bpf/verifier.c:1440 [inline] copy_func_state kernel/bpf/verifier.c:1726 [inline] copy_verifier_state+0x848/0xed0 kernel/bpf/verifier.c:1767 pop_stack+0x8f/0x470 kernel/bpf/verifier.c:1999 do_check+0x70a2/0xd630 kernel/bpf/verifier.c:19655 do_check_common+0x168d/0x20b0 kernel/bpf/verifier.c:22776 do_check_main kernel/bpf/verifier.c:22867 [inline] bpf_check+0x13679/0x19a70 kernel/bpf/verifier.c:24033 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2971 __sys_bpf+0x5f1/0x860 kernel/bpf/syscall.c:5834 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline] __se_sys_bpf kernel/bpf/syscall.c:5939 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5939 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff88802afd9a00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88802afd9a80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88802afd9b00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88802afd9b80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ffff88802afd9c00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================