loop2: rw=524288, sector=34359738360, nr_sectors = 8 limit=16 syz.2.120: attempt to access beyond end of device loop2: rw=524288, sector=8, nr_sectors = 16 limit=16 ================================================================== BUG: KASAN: slab-out-of-bounds in memcpy_to_page include/linux/highmem.h:403 [inline] BUG: KASAN: slab-out-of-bounds in z_erofs_transform_plain+0x39c/0x494 fs/erofs/decompressor.c:347 Read of size 4096 at addr ffff0000f4ba5000 by task syz.2.120/5031 CPU: 0 PID: 5031 Comm: syz.2.120 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: dump_backtrace+0x1c4/0x1f0 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+0x39c/0x494 fs/erofs/decompressor.c:347 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:435 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline] z_erofs_decompress_queue+0x103c/0x1bf4 fs/erofs/zdata.c:1240 z_erofs_runqueue+0x1508/0x16a8 fs/erofs/zdata.c:1603 z_erofs_read_folio+0x2dc/0x5cc fs/erofs/zdata.c:1693 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_update_page mm/filemap.c:2575 [inline] filemap_get_pages mm/filemap.c:2689 [inline] filemap_read+0x1290/0x20dc mm/filemap.c:2759 generic_file_read_iter+0xf8/0x5ac mm/filemap.c:2941 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x3cc/0x7b8 fs/read_write.c:470 ksys_read+0x12c/0x228 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:621 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 4338: 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_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x7c/0x94 mm/slab_common.c:1031 kmalloc include/linux/slab.h:563 [inline] kmalloc_array include/linux/slab.h:614 [inline] kcalloc include/linux/slab.h:646 [inline] nsim_dev_traps_init+0x104/0x434 drivers/net/netdevsim/dev.c:879 nsim_drv_probe+0x528/0x980 drivers/net/netdevsim/dev.c:1579 nsim_bus_probe+0x20/0x30 drivers/net/netdevsim/bus.c:239 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x3a0/0xac4 drivers/base/dd.c:638 __driver_probe_device+0x1c8/0x368 drivers/base/dd.c:804 driver_probe_device+0x78/0x324 drivers/base/dd.c:834 __device_attach_driver+0x28c/0x4c0 drivers/base/dd.c:962 bus_for_each_drv+0x154/0x1e4 drivers/base/bus.c:429 __device_attach+0x2a4/0x3d8 drivers/base/dd.c:1034 device_initial_probe+0x24/0x34 drivers/base/dd.c:1083 bus_probe_device+0xbc/0x1c4 drivers/base/bus.c:489 device_add+0x93c/0xe4c drivers/base/core.c:3712 device_register+0x28/0x38 drivers/base/core.c:3794 nsim_bus_dev_new drivers/net/netdevsim/bus.c:290 [inline] new_device_store+0x2dc/0x52c drivers/net/netdevsim/bus.c:167 bus_attr_store+0x80/0xa4 drivers/base/bus.c:124 sysfs_kf_write+0x1f8/0x274 fs/sysfs/file.c:140 kernfs_fop_write_iter+0x390/0x4b4 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x7c8 fs/read_write.c:584 ksys_write+0x12c/0x228 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the object at ffff0000f4ba5000 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 0 bytes inside of 128-byte region [ffff0000f4ba5000, ffff0000f4ba5080) The buggy address belongs to the physical page: page:0000000081eb3b45 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x134ba5 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c0002300 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f4ba4f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000f4ba4f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000f4ba5000: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff0000f4ba5080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000f4ba5100: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ================================================================== syz.2.120: attempt to access beyond end of device loop2: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.2.120: attempt to access beyond end of device loop2: rw=0, sector=34359738360, nr_sectors = 8 limit=16