================================================================== 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 ffff88802e21d160 by task kswapd0/83 CPU: 1 PID: 83 Comm: kswapd0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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+0x205/0x520 fs/buffer.c:2826 shrink_folio_list+0x209e/0x7ae0 mm/vmscan.c:2003 evict_folios+0xa76/0x2270 mm/vmscan.c:5046 lru_gen_shrink_lruvec mm/vmscan.c:5229 [inline] shrink_lruvec+0xbdd/0x3c60 mm/vmscan.c:5924 Allocated by task 4829: 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:3659 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:1613 filename_create+0x21e/0x450 fs/namei.c:3885 do_mkdirat+0x9d/0x430 fs/namei.c:4129 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152 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 ffff88802e21d100 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes to the right of 96-byte region [ffff88802e21d100, ffff88802e21d160) The buggy address belongs to the physical page: page:ffffea0000b88740 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2e21d flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000001 ffff888017441780 raw: 0000000000000000 0000000000200020 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 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 7, tgid 7 (kworker/0:0), ts 76183702278, free_ts 74877924498 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] dst_cow_metrics_generic+0x52/0x1b0 net/core/dst.c:202 dst_metrics_write_ptr include/net/dst.h:119 [inline] dst_metric_set include/net/dst.h:180 [inline] icmp6_dst_alloc+0x2d8/0x460 net/ipv6/route.c:3321 ndisc_send_skb+0x3ff/0x1510 net/ipv6/ndisc.c:493 ndisc_send_ns+0xc8/0x150 net/ipv6/ndisc.c:671 addrconf_dad_work+0xa15/0x14d0 net/ipv6/addrconf.c:4219 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 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+0x14d/0x320 mm/slub.c:3404 __alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1271 [inline] mld_newpack+0x12a/0xc60 net/ipv6/mcast.c:1745 add_grhead+0x5a/0x2a0 net/ipv6/mcast.c:1856 add_grec+0x13b2/0x1660 net/ipv6/mcast.c:1994 mld_send_initial_cr+0xed/0x240 net/ipv6/mcast.c:2241 mld_dad_work+0x3c/0x270 net/ipv6/mcast.c:2267 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 Memory state around the buggy address: ffff88802e21d000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88802e21d080: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88802e21d100: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ^ ffff88802e21d180: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88802e21d200: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================