loop5: rw=524288, sector=88, nr_sectors = 48 limit=16
syz.5.771: attempt to access beyond end of device
loop5: rw=524288, sector=8, nr_sectors = 80 limit=16
==================================================================
BUG: KASAN: use-after-free in memcpy_to_page include/linux/highmem.h:403 [inline]
BUG: KASAN: use-after-free in z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346
Read of size 4096 at addr ffff0000f64a3000 by task syz.5.771/7806

CPU: 1 PID: 7806 Comm: syz.5.771 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Call trace:
 dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 print_address_description+0x88/0x218 mm/kasan/report.c:316
 print_report+0x50/0x68 mm/kasan/report.c:420
 kasan_report+0xa8/0xfc mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x258/0x290 mm/kasan/generic.c:189
 memcpy+0x48/0x90 mm/kasan/shadow.c:65
 memcpy_to_page include/linux/highmem.h:403 [inline]
 z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346
 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:434
 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline]
 z_erofs_decompress_queue+0x100c/0x1b40 fs/erofs/zdata.c:1240
 z_erofs_runqueue+0x1510/0x1694 fs/erofs/zdata.c:-1
 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1687
 filemap_read_folio+0x134/0x384 mm/filemap.c:2490
 filemap_fault+0x98c/0xe98 mm/filemap.c:3340
 __do_fault+0x11c/0x3d8 mm/memory.c:4278
 do_read_fault mm/memory.c:4629 [inline]
 do_fault mm/memory.c:4758 [inline]
 handle_pte_fault mm/memory.c:5029 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x1cac/0x2fb0 mm/memory.c:5292
 __do_page_fault arch/arm64/mm/fault.c:499 [inline]
 do_page_fault+0x310/0x98c arch/arm64/mm/fault.c:583
 do_translation_fault+0x94/0xc8 arch/arm64/mm/fault.c:667
 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:804
 el0_da+0x70/0x144 arch/arm64/kernel/entry-common.c:515
 el0t_64_sync_handler+0x90/0xf0 arch/arm64/kernel/entry-common.c:658
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Allocated by task 55:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:53
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505
 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x74/0x430 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 kmem_cache_alloc_node+0x250/0x33c mm/slub.c:3404
 __alloc_skb+0x128/0x714 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1271 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x214/0x984 drivers/net/netdevsim/dev.c:851
 process_one_work+0x7f8/0x13a4 kernel/workqueue.c:2292
 worker_thread+0x8c4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

Freed by task 55:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:53
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516
 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 kmem_cache_free+0x118/0x314 mm/slub.c:3709
 kfree_skbmem+0x10c/0x198 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:871 [inline]
 consume_skb+0xa8/0x104 net/core/skbuff.c:1035
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
 nsim_dev_trap_report_work+0x630/0x984 drivers/net/netdevsim/dev.c:851
 process_one_work+0x7f8/0x13a4 kernel/workqueue.c:2292
 worker_thread+0x8c4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

The buggy address belongs to the object at ffff0000f64a3000
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 0 bytes inside of
 240-byte region [ffff0000f64a3000, ffff0000f64a30f0)

The buggy address belongs to the physical page:
page:00000000e3d8ede0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1364a3
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 fffffc0003c93bc0 dead000000000003 ffff0000c086c180
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f64a2f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000f64a2f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000f64a3000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000f64a3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff0000f64a3100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================