================================================================== BUG: KASAN: slab-out-of-bounds in copy_page_from_iter_atomic+0x8e3/0x1230 lib/iov_iter.c:978 Read of size 1024 at addr ffff88807abfec00 by task kworker/u4:4/1237 CPU: 0 PID: 1237 Comm: kworker/u4:4 Not tainted 5.15.158-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: loop0 loop_rootcg_workfn Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 kasan_check_range+0x27e/0x290 mm/kasan/generic.c:189 memcpy+0x25/0x60 mm/kasan/shadow.c:65 copy_page_from_iter_atomic+0x8e3/0x1230 lib/iov_iter.c:978 generic_perform_write+0x33a/0x5b0 mm/filemap.c:3793 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944 do_iter_readv_writev+0x594/0x7a0 do_iter_write+0x1ea/0x760 fs/read_write.c:855 lo_write_bvec+0x297/0x740 drivers/block/loop.c:316 lo_write_simple drivers/block/loop.c:338 [inline] do_req_filebacked drivers/block/loop.c:656 [inline] loop_handle_cmd drivers/block/loop.c:2234 [inline] loop_process_work+0x2309/0x2af0 drivers/block/loop.c:2274 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Allocated by task 3500: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513 kasan_kmalloc include/linux/kasan.h:264 [inline] __kmalloc+0x168/0x300 mm/slub.c:4407 kmalloc include/linux/slab.h:596 [inline] hfsplus_read_wrapper+0x4e3/0x13b0 fs/hfsplus/wrapper.c:180 hfsplus_fill_super+0x38a/0x1c90 fs/hfsplus/super.c:413 mount_bdev+0x2c9/0x3f0 fs/super.c:1387 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1517 do_new_mount+0x2ba/0xb40 fs/namespace.c:3005 do_mount fs/namespace.c:3348 [inline] __do_sys_mount fs/namespace.c:3556 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3533 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88807abfec00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff88807abfec00, ffff88807abfee00) The buggy address belongs to the page: page:ffffea0001eaff00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7abfc head:ffffea0001eaff00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000a00000001 ffff888011c41c80 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2964, ts 13748145428, free_ts 11348326457 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc_trace+0x1a0/0x290 mm/slub.c:3245 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] kernfs_fop_open+0x3b5/0xbc0 fs/kernfs/file.c:628 do_dentry_open+0x807/0xfb0 fs/open.c:826 do_open fs/namei.c:3608 [inline] path_openat+0x2705/0x2f20 fs/namei.c:3742 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x500 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_contig_range+0x95/0xf0 mm/page_alloc.c:9342 destroy_args+0xfe/0x980 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x40d/0x470 mm/debug_vm_pgtable.c:1331 do_one_initcall+0x22b/0x7a0 init/main.c:1302 do_initcall_level+0x157/0x210 init/main.c:1375 do_initcalls+0x49/0x90 init/main.c:1391 kernel_init_freeable+0x425/0x5c0 init/main.c:1615 kernel_init+0x19/0x290 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Memory state around the buggy address: ffff88807abfed00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807abfed80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807abfee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88807abfee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807abfef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================