================================================================== BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x1c1/0x5a0 lib/iov_iter.c:633 Read of size 4 at addr ffff88807bd20178 by task kworker/u8:10/6960 CPU: 0 UID: 0 PID: 6960 Comm: kworker/u8:10 Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #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: __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 Allocated by task 5201: 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:4341 [inline] __kmalloc_noprof+0x28e/0x4d0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x25a/0x4f0 security/tomoyo/file.c:771 security_file_open+0xac/0x250 security/security.c:3114 do_dentry_open+0x320/0x1960 fs/open.c:933 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x2caf/0x35d0 fs/namei.c:4039 do_filp_open+0x284/0x4e0 fs/namei.c:4066 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x249/0x2a0 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5201: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2398 [inline] slab_free mm/slub.c:4656 [inline] kfree+0x198/0x430 mm/slub.c:4855 tomoyo_check_open_permission+0x361/0x4f0 security/tomoyo/file.c:786 security_file_open+0xac/0x250 security/security.c:3114 do_dentry_open+0x320/0x1960 fs/open.c:933 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x2caf/0x35d0 fs/namei.c:4039 do_filp_open+0x284/0x4e0 fs/namei.c:4066 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x249/0x2a0 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807bd20140 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 [ffff88807bd20140, ffff88807bd20160) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bd20 ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b041780 ffffea0001f21280 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 5791, tgid 5791 (cmp), ts 76146568877, free_ts 76110912974 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x360d/0x37b0 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4970 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2468 [inline] allocate_slab+0x8f/0x3b0 mm/slub.c:2632 new_slab mm/slub.c:2686 [inline] ___slab_alloc+0xc3b/0x1500 mm/slub.c:3872 __slab_alloc+0x58/0xa0 mm/slub.c:3962 __slab_alloc_node mm/slub.c:4037 [inline] slab_alloc_node mm/slub.c:4198 [inline] __kmalloc_cache_noprof+0x26a/0x370 mm/slub.c:4367 kmalloc_noprof include/linux/slab.h:905 [inline] slab_free_hook mm/slub.c:2350 [inline] slab_free mm/slub.c:4656 [inline] kmem_cache_free+0x16e/0x410 mm/slub.c:4758 fput_close+0x1f2/0x270 fs/file_table.c:582 path_openat+0x2f18/0x35d0 fs/namei.c:4048 do_filp_open+0x284/0x4e0 fs/namei.c:4066 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x249/0x2a0 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5789 tgid 5789 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:2725 pagetable_free include/linux/mm.h:3019 [inline] pagetable_dtor_free include/linux/mm.h:3117 [inline] __tlb_remove_table+0x36b/0x460 include/asm-generic/tlb.h:215 __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x79/0xf0 mm/mmu_gather.c:290 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0xaac/0x17a0 kernel/rcu/tree.c:2824 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0xa3/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 Memory state around the buggy address: ffff88807bd20000: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ffff88807bd20080: 00 00 00 fc fc fc fc fc 00 00 00 00 fc fc fc fc >ffff88807bd20100: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88807bd20180: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ffff88807bd20200: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc ==================================================================