================================================================== BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x1c1/0x5a0 lib/iov_iter.c:633 Read of size 4 at addr ffff8880309c73b8 by task kworker/u8:1/13 CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.15.0-rc2-syzkaller-00048-gc62f4b82d571 #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+0xac5/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 8061: 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] __kmalloc_cache_noprof+0x236/0x370 mm/slub.c:4362 kmalloc_noprof include/linux/slab.h:905 [inline] proc_self_get_link+0xe0/0x170 fs/proc/self.c:22 pick_link+0x6b2/0xdc0 fs/namei.c:1928 step_into+0xc5f/0x1000 fs/namei.c:1998 walk_component fs/namei.c:2134 [inline] link_path_walk+0x72f/0xeb0 fs/namei.c:2493 path_openat+0x26d/0x35d0 fs/namei.c:4000 do_filp_open+0x284/0x4e0 fs/namei.c:4031 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+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8061: 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:2389 [inline] slab_free mm/slub.c:4646 [inline] kfree+0x198/0x430 mm/slub.c:4845 do_delayed_call include/linux/delayed_call.h:28 [inline] put_link fs/namei.c:1093 [inline] walk_component+0x182/0x420 fs/namei.c:2133 link_path_walk+0x705/0xeb0 fs/namei.c:2490 path_openat+0x26d/0x35d0 fs/namei.c:4000 do_filp_open+0x284/0x4e0 fs/namei.c:4031 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+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880309c73a0 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 [ffff8880309c73a0, ffff8880309c73b0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x309c7 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b041640 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000800080 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 5832, tgid 5832 (syz-executor), ts 102046450257, free_ts 102021137896 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1717 prep_new_page mm/page_alloc.c:1725 [inline] get_page_from_freelist+0x352b/0x36c0 mm/page_alloc.c:3652 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2459 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2623 new_slab mm/slub.c:2676 [inline] ___slab_alloc+0xc3b/0x1500 mm/slub.c:3862 __slab_alloc+0x58/0xa0 mm/slub.c:3952 __slab_alloc_node mm/slub.c:4027 [inline] slab_alloc_node mm/slub.c:4188 [inline] __do_kmalloc_node mm/slub.c:4330 [inline] __kmalloc_noprof+0x2ea/0x4d0 mm/slub.c:4343 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] xt_jumpstack_alloc net/netfilter/x_tables.c:1335 [inline] xt_replace_table+0x91/0x780 net/netfilter/x_tables.c:1394 __do_replace+0x1b0/0xa60 net/ipv4/netfilter/ip_tables.c:1064 do_replace net/ipv4/netfilter/ip_tables.c:1141 [inline] do_ipt_set_ctl+0xf09/0x1260 net/ipv4/netfilter/ip_tables.c:1635 nf_setsockopt+0x297/0x2c0 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x3b3/0x710 net/socket.c:2296 __sys_setsockopt net/socket.c:2321 [inline] __do_sys_setsockopt net/socket.c:2327 [inline] __se_sys_setsockopt net/socket.c:2324 [inline] __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 3 tgid 3 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0xde8/0x10a0 mm/page_alloc.c:2680 pagetable_free include/linux/mm.h:3002 [inline] pagetable_dtor_free include/linux/mm.h:3100 [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+0xaae/0x17a0 kernel/rcu/tree.c:2824 handle_softirqs+0x2d8/0x9b0 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_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Memory state around the buggy address: ffff8880309c7280: 00 00 fc fc 00 00 fc fc fa fb fc fc fa fb fc fc ffff8880309c7300: fa fb fc fc 00 00 fc fc 00 00 fc fc fa fb fc fc >ffff8880309c7380: fa fb fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc ^ ffff8880309c7400: 00 00 fc fc fa fb fc fc fa fb fc fc 00 00 fc fc ffff8880309c7480: fa fb fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ==================================================================