================================================================== 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 ffff8880363603b8 by task kworker/u8:8/2992 CPU: 0 UID: 0 PID: 2992 Comm: kworker/u8:8 Not tainted 6.15.0-rc5-syzkaller #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 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+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 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 Allocated by task 7046: 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 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+0x148/0x4d0 mm/slub.c:4744 p9_req_put net/9p/client.c:409 [inline] p9_req_put+0x1c6/0x250 net/9p/client.c:402 p9_client_write+0x32b/0x6f0 net/9p/client.c:1674 v9fs_issue_write+0xe3/0x1b0 fs/9p/vfs_addr.c:59 netfs_do_issue_write+0x92/0x110 fs/netfs/write_issue.c:239 netfs_issue_write fs/netfs/write_issue.c:269 [inline] netfs_end_issue_write+0x14c/0x200 fs/netfs/write_issue.c:541 netfs_unbuffered_write+0x4c3/0x670 fs/netfs/write_issue.c:733 netfs_unbuffered_write_iter_locked+0x808/0xd40 fs/netfs/direct_write.c:100 netfs_unbuffered_write_iter+0x414/0x6d0 fs/netfs/direct_write.c:195 v9fs_file_write_iter+0xbf/0x100 fs/9p/vfs_file.c:404 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x5ba/0x1180 fs/read_write.c:684 ksys_write+0x12a/0x240 fs/read_write.c:736 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 15: 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:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4841 slab_free_after_rcu_debug+0x69/0x350 mm/slub.c:4679 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0x799/0x14e0 kernel/rcu/tree.c:2824 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 run_ksoftirqd kernel/softirq.c:968 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960 smpboot_thread_fn+0x3f4/0xae0 kernel/smpboot.c:164 kthread+0x3c2/0x780 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 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xb8/0xd0 mm/kasan/generic.c:548 __call_rcu_common.constprop.0+0x9a/0x9f0 kernel/rcu/tree.c:3082 slab_free_hook mm/slub.c:2344 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x173/0x4d0 mm/slub.c:4744 p9_req_put net/9p/client.c:409 [inline] p9_req_put+0x1c6/0x250 net/9p/client.c:402 p9_client_write+0x32b/0x6f0 net/9p/client.c:1674 v9fs_issue_write+0xe3/0x1b0 fs/9p/vfs_addr.c:59 netfs_do_issue_write+0x92/0x110 fs/netfs/write_issue.c:239 netfs_issue_write fs/netfs/write_issue.c:269 [inline] netfs_end_issue_write+0x14c/0x200 fs/netfs/write_issue.c:541 netfs_unbuffered_write+0x4c3/0x670 fs/netfs/write_issue.c:733 netfs_unbuffered_write_iter_locked+0x808/0xd40 fs/netfs/direct_write.c:100 netfs_unbuffered_write_iter+0x414/0x6d0 fs/netfs/direct_write.c:195 v9fs_file_write_iter+0xbf/0x100 fs/9p/vfs_file.c:404 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x5ba/0x1180 fs/read_write.c:684 ksys_write+0x12a/0x240 fs/read_write.c:736 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 ffff888036360380 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 [ffff888036360380, ffff8880363603a0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x36360 ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b441780 ffffea0001f7a800 dead000000000003 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 5260, tgid 5260 (udevd), ts 25952625895, free_ts 25950997517 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4970 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab mm/slub.c:2618 [inline] new_slab+0x244/0x340 mm/slub.c:2672 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948 __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 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+0x148/0x4d0 mm/slub.c:4744 exit_mmap+0x511/0xb90 mm/mmap.c:1309 __mmput+0x12a/0x410 kernel/fork.c:1379 mmput+0x62/0x70 kernel/fork.c:1401 exec_mmap fs/exec.c:1009 [inline] begin_new_exec+0x15a7/0x38b0 fs/exec.c:1264 load_elf_binary+0x88c/0x4f80 fs/binfmt_elf.c:1001 search_binary_handler fs/exec.c:1778 [inline] exec_binprm fs/exec.c:1810 [inline] bprm_execve fs/exec.c:1862 [inline] bprm_execve+0x8c0/0x1650 fs/exec.c:1838 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1968 page last free pid 5260 tgid 5260 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2725 tlb_batch_list_free mm/mmu_gather.c:159 [inline] tlb_finish_mmu+0x237/0x7b0 mm/mmu_gather.c:499 exit_mmap+0x403/0xb90 mm/mmap.c:1297 __mmput+0x12a/0x410 kernel/fork.c:1379 mmput+0x62/0x70 kernel/fork.c:1401 exec_mmap fs/exec.c:1009 [inline] begin_new_exec+0x15a7/0x38b0 fs/exec.c:1264 load_elf_binary+0x88c/0x4f80 fs/binfmt_elf.c:1001 search_binary_handler fs/exec.c:1778 [inline] exec_binprm fs/exec.c:1810 [inline] bprm_execve fs/exec.c:1862 [inline] bprm_execve+0x8c0/0x1650 fs/exec.c:1838 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1968 do_execve fs/exec.c:2042 [inline] __do_sys_execve fs/exec.c:2118 [inline] __se_sys_execve fs/exec.c:2113 [inline] __x64_sys_execve+0x8e/0xb0 fs/exec.c:2113 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 Memory state around the buggy address: ffff888036360280: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff888036360300: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff888036360380: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ^ ffff888036360400: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff888036360480: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================