================================================================== BUG: KASAN: slab-out-of-bounds in instrument_atomic_read include/linux/instrumented.h:72 [inline] BUG: KASAN: slab-out-of-bounds in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] BUG: KASAN: slab-out-of-bounds in buffer_busy fs/buffer.c:2784 [inline] BUG: KASAN: slab-out-of-bounds in drop_buffers+0x65/0x6a0 fs/buffer.c:2796 Read of size 4 at addr ffff88807665d8e0 by task syz.2.39/4540 CPU: 0 PID: 4540 Comm: syz.2.39 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x27b/0x290 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:72 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] buffer_busy fs/buffer.c:2784 [inline] drop_buffers+0x65/0x6a0 fs/buffer.c:2796 try_to_free_buffers+0x171/0x520 fs/buffer.c:2831 mapping_evict_folio+0x229/0x520 mm/truncate.c:278 invalidate_mapping_pagevec+0x335/0x660 mm/truncate.c:527 drop_pagecache_sb+0x19a/0x230 fs/drop_caches.c:39 iterate_supers+0x11e/0x1d0 fs/super.c:757 drop_caches_sysctl_handler+0x8e/0x160 fs/drop_caches.c:62 proc_sys_call_handler+0x458/0x6c0 fs/proc/proc_sysctl.c:602 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x62d/0xaf0 fs/read_write.c:861 iter_file_splice_write+0x665/0xc50 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0xe1/0x130 fs/splice.c:950 splice_direct_to_actor+0x480/0xb60 fs/splice.c:896 do_splice_direct+0x1b0/0x2b0 fs/splice.c:1002 do_sendfile+0x5cc/0xeb0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64+0xd6/0x190 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1eb218ec29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe85dc25e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f1eb23d5fa0 RCX: 00007f1eb218ec29 RDX: 0000200000002080 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f1eb2211e41 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000023b R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1eb23d5fa0 R14: 00007f1eb23d5fa0 R15: 0000000000000004 Allocated by task 4539: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc+0xb0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] iomap_page_create+0x14a/0x600 fs/iomap/buffered-io.c:61 iomap_readpage_iter+0x240/0x8f0 fs/iomap/buffered-io.c:273 iomap_read_folio+0x2e7/0x7f0 fs/iomap/buffered-io.c:344 filemap_read_folio+0x160/0x760 mm/filemap.c:2490 do_read_cache_folio+0x2a0/0x760 mm/filemap.c:3627 erofs_bread+0x18e/0x670 fs/erofs/data.c:50 erofs_find_target_block fs/erofs/namei.c:102 [inline] erofs_namei+0x28f/0xf00 fs/erofs/namei.c:175 erofs_lookup+0x14b/0x390 fs/erofs/namei.c:204 lookup_one_qstr_excl+0x10e/0x240 fs/namei.c:1605 filename_create+0x21e/0x450 fs/namei.c:3877 do_mknodat+0x16e/0x4c0 fs/namei.c:4022 __do_sys_mknod fs/namei.c:4068 [inline] __se_sys_mknod fs/namei.c:4066 [inline] __x64_sys_mknod+0x8a/0xa0 fs/namei.c:4066 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807665d880 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes to the right of 96-byte region [ffff88807665d880, ffff88807665d8e0) The buggy address belongs to the physical page: page:ffffea0001d99740 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7665d flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001cf8b00 dead000000000002 ffff888017441780 raw: 0000000000000000 0000000080200020 00000001ffffffff 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 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 4391, tgid 4391 (syz-executor), ts 89997991153, free_ts 89976810442 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1230 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:990 [inline] nsim_fib_event_nb+0xe3/0x1040 drivers/net/netdevsim/fib.c:1043 notifier_call_chain kernel/notifier.c:87 [inline] atomic_notifier_call_chain+0x17a/0x2b0 kernel/notifier.c:225 call_fib_notifiers+0x2d/0x60 net/core/fib_notifier.c:35 call_fib_entry_notifiers+0x148/0x1f0 net/ipv4/fib_trie.c:106 fib_table_insert+0xca4/0x1b50 net/ipv4/fib_trie.c:1375 fib_magic+0x2c1/0x390 net/ipv4/fib_frontend.c:1118 fib_add_ifaddr+0x140/0x5e0 net/ipv4/fib_frontend.c:1140 fib_inetaddr_event+0x13c/0x1c0 net/ipv4/fib_frontend.c:1454 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] __kmem_cache_alloc_node+0x140/0x260 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] fib6_info_alloc+0x2e/0xe0 net/ipv6/ip6_fib.c:156 ip6_route_info_create+0x44f/0x1210 net/ipv6/route.c:3794 ip6_route_add+0x24/0x130 net/ipv6/route.c:3890 addrconf_add_mroute net/ipv6/addrconf.c:2506 [inline] addrconf_add_dev+0x253/0x330 net/ipv6/addrconf.c:2524 addrconf_gre_config net/ipv6/addrconf.c:3474 [inline] addrconf_init_auto_addrs+0x19b/0xa60 net/ipv6/addrconf.c:3504 addrconf_notify+0xaca/0xf40 net/ipv6/addrconf.c:3685 Memory state around the buggy address: ffff88807665d780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88807665d800: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88807665d880: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ^ ffff88807665d900: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88807665d980: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================