================================================================== 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 ffff8880761b47e0 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 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x24e 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+0x235/0x290 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+0x2127/0x7aa0 mm/vmscan.c:2003 evict_folios+0xa80/0x22a0 mm/vmscan.c:5046 lru_gen_shrink_lruvec mm/vmscan.c:5229 [inline] shrink_lruvec+0xc90/0x3d50 mm/vmscan.c:5924 Allocated by task 4382: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 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+0x332/0x8c0 fs/iomap/buffered-io.c:344 filemap_read_folio+0x16b/0x770 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+0x29c/0xf50 fs/erofs/namei.c:175 erofs_lookup+0x14b/0x390 fs/erofs/namei.c:204 lookup_open fs/namei.c:3468 [inline] open_last_lookups fs/namei.c:3558 [inline] path_openat+0xfce/0x2ee0 fs/namei.c:3788 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff8880761b4780 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes to the right of 96-byte region [ffff8880761b4780, ffff8880761b47e0) The buggy address belongs to the physical page: page:ffffea0001d86d00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880761b4b00 pfn:0x761b4 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea000123ae48 ffffea00009e3a88 ffff888017441780 raw: ffff8880761b4b00 000000000020000d 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 4274, tgid 4274 (syz-executor), ts 77639610611, free_ts 75126244555 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5643 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+0xbc6/0x1240 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+0x424/0x14e0 net/ipv6/ndisc.c:493 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3979 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1486 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508 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:306 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] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3383 mt_alloc_one lib/maple_tree.c:154 [inline] mas_alloc_nodes+0x2ec/0x890 lib/maple_tree.c:1279 mas_node_count_gfp lib/maple_tree.c:1361 [inline] mas_preallocate+0x161/0x3c0 lib/maple_tree.c:5809 vma_expand+0x27a/0x880 mm/mmap.c:544 __mmap_region mm/mmap.c:2740 [inline] mmap_region+0xbd2/0x1ca0 mm/mmap.c:2916 do_mmap+0x964/0xfd0 mm/mmap.c:1436 vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:520 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482 Memory state around the buggy address: ffff8880761b4680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880761b4700: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8880761b4780: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ^ ffff8880761b4800: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880761b4880: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ==================================================================