=====================================================
BUG: KMSAN: uninit-value in sw842_compress+0xe81/0x5a90 lib/842/842_compress.c:528
 sw842_compress+0xe81/0x5a90 lib/842/842_compress.c:528
 crypto842_scompress+0x4f/0x70 crypto/842.c:50
 scomp_acomp_comp_decomp+0xa8d/0xd90 crypto/scompress.c:-1
 scomp_acomp_chain crypto/scompress.c:297 [inline]
 scomp_acomp_compress+0x3c/0x1f0 crypto/scompress.c:308
 acomp_do_req_chain+0x39a/0x9f0 crypto/acompress.c:353
 crypto_acomp_compress+0x5f/0x80 crypto/acompress.c:372
 zswap_compress mm/zswap.c:962 [inline]
 zswap_store_page mm/zswap.c:1462 [inline]
 zswap_store+0x20a1/0x4860 mm/zswap.c:1571
 swap_writepage+0xa7c/0x1980 mm/page_io.c:278
 shmem_writepage+0x234a/0x2590 mm/shmem.c:1647
 pageout mm/vmscan.c:696 [inline]
 shrink_folio_list+0x5ddb/0x8220 mm/vmscan.c:1402
 evict_folios+0x9567/0xba40 mm/vmscan.c:4660
 try_to_shrink_lruvec+0xc6a/0x1090 mm/vmscan.c:4821
 lru_gen_shrink_lruvec mm/vmscan.c:4970 [inline]
 shrink_lruvec+0x4a7/0x4880 mm/vmscan.c:5715
 shrink_node_memcgs mm/vmscan.c:5951 [inline]
 shrink_node+0x1064/0x51d0 mm/vmscan.c:5992
 shrink_zones mm/vmscan.c:6237 [inline]
 do_try_to_free_pages+0x820/0x2550 mm/vmscan.c:6299
 try_to_free_mem_cgroup_pages+0x3fd/0xa60 mm/vmscan.c:6631
 try_charge_memcg+0x71a/0x1780 mm/memcontrol.c:2264
 obj_cgroup_charge_pages+0x2cb/0x640 mm/memcontrol.c:2645
 __memcg_kmem_charge_page+0x151/0x520 mm/memcontrol.c:2672
 __alloc_frozen_pages_noprof+0x93d/0xe00 mm/page_alloc.c:4757
 alloc_pages_mpol+0x4cd/0x890 mm/mempolicy.c:2301
 alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline]
 alloc_pages_noprof+0x1b5/0x250 mm/mempolicy.c:2392
 io_mem_alloc_compound io_uring/memmap.c:29 [inline]
 io_region_allocate_pages+0x168/0x8b0 io_uring/memmap.c:167
 io_create_region+0x6eb/0x810 io_uring/memmap.c:223
 io_allocate_scq_urings+0x777/0xa50 io_uring/io_uring.c:3532
 io_uring_create+0xb23/0x1470 io_uring/io_uring.c:3738
 io_uring_setup io_uring/io_uring.c:3828 [inline]
 __do_sys_io_uring_setup io_uring/io_uring.c:3862 [inline]
 __se_sys_io_uring_setup+0x4f5/0x560 io_uring/io_uring.c:3853
 __x64_sys_io_uring_setup+0x6c/0xa0 io_uring/io_uring.c:3853
 x64_sys_call+0x1aea/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:426
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 memcpy_from_iter lib/iov_iter.c:73 [inline]
 iterate_bvec include/linux/iov_iter.h:123 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:304 [inline]
 iterate_and_advance include/linux/iov_iter.h:328 [inline]
 __copy_from_iter lib/iov_iter.c:249 [inline]
 copy_page_from_iter_atomic+0x1313/0x3450 lib/iov_iter.c:483
 copy_folio_from_iter_atomic include/linux/uio.h:210 [inline]
 generic_perform_write+0x83f/0x1060 mm/filemap.c:4132
 shmem_file_write_iter+0x2ba/0x2f0 mm/shmem.c:3477
 do_iter_readv_writev+0x93d/0xbc0 fs/read_write.c:-1
 vfs_iter_write+0x44d/0xd60 fs/read_write.c:979
 lo_write_bvec drivers/block/loop.c:221 [inline]
 lo_write_simple drivers/block/loop.c:242 [inline]
 do_req_filebacked drivers/block/loop.c:496 [inline]
 loop_handle_cmd drivers/block/loop.c:1943 [inline]
 loop_process_work+0x1606/0x3780 drivers/block/loop.c:1978
 loop_workfn+0x48/0x60 drivers/block/loop.c:2002
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xc1d/0x1e80 kernel/workqueue.c:3319
 worker_thread+0xea3/0x1500 kernel/workqueue.c:3400
 kthread+0x6ce/0xf10 kernel/kthread.c:464
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Uninit was created at:
 __alloc_frozen_pages_noprof+0x9a7/0xe00 mm/page_alloc.c:4763
 __alloc_pages_noprof mm/page_alloc.c:4774 [inline]
 alloc_pages_bulk_noprof+0x122d/0x1a70 mm/page_alloc.c:4694
 btrfs_alloc_page_array fs/btrfs/extent_io.c:631 [inline]
 alloc_eb_folio_array+0x199/0x750 fs/btrfs/extent_io.c:655
 alloc_extent_buffer+0x611/0x3000 fs/btrfs/extent_io.c:3273
 btrfs_find_create_tree_block+0x46/0x60 fs/btrfs/disk-io.c:612
 btrfs_init_new_buffer fs/btrfs/extent-tree.c:5019 [inline]
 btrfs_alloc_tree_block+0x415/0x19d0 fs/btrfs/extent-tree.c:5132
 btrfs_alloc_log_tree_node fs/btrfs/disk-io.c:948 [inline]
 btrfs_add_log_tree+0x1b7/0x7a0 fs/btrfs/disk-io.c:996
 start_log_trans fs/btrfs/tree-log.c:227 [inline]
 btrfs_log_inode_parent+0xa99/0x1c30 fs/btrfs/tree-log.c:7064
 btrfs_log_dentry_safe+0x9a/0x100 fs/btrfs/tree-log.c:7170
 btrfs_sync_file+0x1676/0x2180 fs/btrfs/file.c:1653
 vfs_fsync_range+0x1f9/0x260 fs/sync.c:187
 generic_write_sync include/linux/fs.h:2976 [inline]
 btrfs_do_write_iter+0xab2/0xc90 fs/btrfs/file.c:1390
 btrfs_file_write_iter+0x38/0x50 fs/btrfs/file.c:1400
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0xb34/0x1540 fs/read_write.c:684
 ksys_write+0x240/0x4b0 fs/read_write.c:736
 __do_sys_write fs/read_write.c:747 [inline]
 __se_sys_write fs/read_write.c:744 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:744
 x64_sys_call+0x34de/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 6675 Comm: syz.5.153 Not tainted 6.14.0-syzkaller-09881-g092e335082f2 #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
=====================================================