=====================================================
BUG: KMSAN: uninit-value in btrfs_comp_cpu_keys fs/btrfs/ctree.c:753 [inline]
BUG: KMSAN: uninit-value in comp_keys fs/btrfs/ctree.c:729 [inline]
BUG: KMSAN: uninit-value in generic_bin_search+0x784/0xb80 fs/btrfs/ctree.c:913
 btrfs_comp_cpu_keys fs/btrfs/ctree.c:753 [inline]
 comp_keys fs/btrfs/ctree.c:729 [inline]
 generic_bin_search+0x784/0xb80 fs/btrfs/ctree.c:913
 search_for_key_slot fs/btrfs/ctree.c:1872 [inline]
 btrfs_search_slot+0x1caa/0x4710 fs/btrfs/ctree.c:2184
 btrfs_lookup_file_extent+0xe5/0x120 fs/btrfs/file-item.c:269
 btrfs_drop_extents+0x557/0x5b50 fs/btrfs/file.c:250
 cow_file_range_inline+0x5d7/0x1150 fs/btrfs/inode.c:471
 compress_file_range+0x1006/0x34c0
 async_cow_start+0x37/0xd0 fs/btrfs/inode.c:1494
 btrfs_work_helper+0x51e/0x17c0 fs/btrfs/async-thread.c:280
 process_one_work+0xb0d/0x1410 kernel/workqueue.c:2289
 worker_thread+0x107b/0x1d60 kernel/workqueue.c:2436
 kthread+0x31f/0x430 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Uninit was created at:
 __alloc_pages+0x9f6/0xe90 mm/page_alloc.c:5572
 alloc_pages+0xab0/0xd80 mm/mempolicy.c:2287
 folio_alloc+0x42/0x120 mm/mempolicy.c:2297
 filemap_alloc_folio+0xb2/0x460 mm/filemap.c:972
 __filemap_get_folio+0xe4b/0x1920 mm/filemap.c:1966
 pagecache_get_page+0x4f/0x290 mm/folio-compat.c:98
 find_or_create_page include/linux/pagemap.h:612 [inline]
 alloc_extent_buffer+0x733/0x3190 fs/btrfs/extent_io.c:4500
 btrfs_find_create_tree_block+0x46/0x60 fs/btrfs/disk-io.c:1002
 btrfs_init_new_buffer fs/btrfs/extent-tree.c:4873 [inline]
 btrfs_alloc_tree_block+0x371/0x1f70 fs/btrfs/extent-tree.c:4992
 __btrfs_cow_block+0x578/0x1f20 fs/btrfs/ctree.c:541
 btrfs_cow_block+0x7cc/0xa00 fs/btrfs/ctree.c:696
 btrfs_search_slot+0x189f/0x4710 fs/btrfs/ctree.c:2141
 btrfs_lookup_file_extent+0xe5/0x120 fs/btrfs/file-item.c:269
 btrfs_drop_extents+0x557/0x5b50 fs/btrfs/file.c:250
 cow_file_range_inline+0x5d7/0x1150 fs/btrfs/inode.c:471
 compress_file_range+0x1006/0x34c0
 async_cow_start+0x37/0xd0 fs/btrfs/inode.c:1494
 btrfs_work_helper+0x51e/0x17c0 fs/btrfs/async-thread.c:280
 process_one_work+0xb0d/0x1410 kernel/workqueue.c:2289
 worker_thread+0x107b/0x1d60 kernel/workqueue.c:2436
 kthread+0x31f/0x430 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

CPU: 1 PID: 2824 Comm: kworker/u4:6 Not tainted 6.2.0-syzkaller-81152-g97e36f4aa06f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Workqueue: btrfs-delalloc btrfs_work_helper
=====================================================