syzbot

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BUG: KASAN: slab-out-of-bounds in memcpy_from_iter lib/iov_iter.c:73 [inline]
BUG: KASAN: slab-out-of-bounds in iterate_bvec include/linux/iov_iter.h:122 [inline]
BUG: KASAN: slab-out-of-bounds in iterate_and_advance2 include/linux/iov_iter.h:249 [inline]
BUG: KASAN: slab-out-of-bounds in iterate_and_advance include/linux/iov_iter.h:271 [inline]
BUG: KASAN: slab-out-of-bounds in __copy_from_iter lib/iov_iter.c:249 [inline]
BUG: KASAN: slab-out-of-bounds in copy_page_from_iter_atomic+0x954/0x1db0 lib/iov_iter.c:481
Read of size 2048 at addr ffff8880157af800 by task kworker/u8:1/11

CPU: 1 PID: 11 Comm: kworker/u8:1 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: loop0 loop_rootcg_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 memcpy_from_iter lib/iov_iter.c:73 [inline]
 iterate_bvec include/linux/iov_iter.h:122 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:249 [inline]
 iterate_and_advance include/linux/iov_iter.h:271 [inline]
 __copy_from_iter lib/iov_iter.c:249 [inline]
 copy_page_from_iter_atomic+0x954/0x1db0 lib/iov_iter.c:481
 generic_perform_write+0x39b/0x640 mm/filemap.c:3938
 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2926
 do_iter_readv_writev+0x5a6/0x800
 vfs_iter_write+0x244/0x5d0 fs/read_write.c:895
 lo_write_bvec drivers/block/loop.c:246 [inline]
 lo_write_simple drivers/block/loop.c:267 [inline]
 do_req_filebacked drivers/block/loop.c:491 [inline]
 loop_handle_cmd drivers/block/loop.c:1907 [inline]
 loop_process_work+0x13a3/0x1e60 drivers/block/loop.c:1942
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa02/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Allocated by task 5071:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slub.c:3966 [inline]
 __kmalloc+0x233/0x4a0 mm/slub.c:3979
 kmalloc include/linux/slab.h:632 [inline]
 hfsplus_read_wrapper+0x545/0x1340 fs/hfsplus/wrapper.c:179
 hfsplus_fill_super+0x38e/0x1ca0 fs/hfsplus/super.c:419
 mount_bdev+0x20c/0x2d0 fs/super.c:1658
 legacy_get_tree+0xf0/0x190 fs/fs_context.c:662
 vfs_get_tree+0x92/0x2a0 fs/super.c:1779
 do_new_mount+0x2be/0xb40 fs/namespace.c:3352
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875
 do_syscall_64+0xfd/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

The buggy address belongs to the object at ffff8880157af800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 allocated 512-byte region [ffff8880157af800, ffff8880157afa00)

The buggy address belongs to the physical page:
page:ffffea000055eb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x157ac
head:ffffea000055eb00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888014c41c80 0000000000000000 dead000000000001
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 1, tgid 1 (swapper/0), ts 3547992935, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
 prep_new_page mm/page_alloc.c:1540 [inline]
 get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
 __alloc_pages+0x256/0x680 mm/page_alloc.c:4569
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2175
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2391
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525
 __slab_alloc mm/slub.c:3610 [inline]
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmalloc_trace+0x269/0x360 mm/slub.c:3992
 kmalloc include/linux/slab.h:628 [inline]
 kzalloc include/linux/slab.h:749 [inline]
 device_private_init drivers/base/core.c:3484 [inline]
 device_add+0xc4/0xca0 drivers/base/core.c:3535
 tty_register_device_attr+0x437/0x960 drivers/tty/tty_io.c:3275
 tty_register_device drivers/tty/tty_io.c:3210 [inline]
 tty_register_driver+0x5f6/0xc30 drivers/tty/tty_io.c:3473
 vty_init+0x1fe/0x300 drivers/tty/vt/vt.c:3564
 tty_init+0x152/0x1a0 drivers/tty/tty_io.c:3664
 do_one_initcall+0x23a/0x830 init/main.c:1241
 do_initcall_level+0x157/0x210 init/main.c:1303
 do_initcalls+0x3f/0x80 init/main.c:1319
 kernel_init_freeable+0x435/0x5d0 init/main.c:1550
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880157af900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880157af980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880157afa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8880157afa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880157afb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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