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BUG: KMSAN: uninit-value in zswap_is_page_same_filled mm/zswap.c:1175 [inline]
BUG: KMSAN: uninit-value in zswap_store+0x17ba/0x32b0 mm/zswap.c:1271
 zswap_is_page_same_filled mm/zswap.c:1175 [inline]
 zswap_store+0x17ba/0x32b0 mm/zswap.c:1271
 swap_writepage+0x122/0x340 mm/page_io.c:198
 shmem_writepage+0x1720/0x1e70 mm/shmem.c:1517
 pageout mm/vmscan.c:654 [inline]
 shrink_folio_list+0x508f/0x7760 mm/vmscan.c:1315
 evict_folios+0x9bb1/0xbaa0 mm/vmscan.c:4499
 try_to_shrink_lruvec+0x15ac/0x1b20 mm/vmscan.c:4704
 shrink_one+0x66e/0xd70 mm/vmscan.c:4743
 shrink_many mm/vmscan.c:4808 [inline]
 lru_gen_shrink_node mm/vmscan.c:4923 [inline]
 shrink_node+0x4bed/0x5890 mm/vmscan.c:5863
 kswapd_shrink_node mm/vmscan.c:6668 [inline]
 balance_pgdat mm/vmscan.c:6858 [inline]
 kswapd+0x1df1/0x4260 mm/vmscan.c:7118
 kthread+0x3ed/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Uninit was stored to memory at:
 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:268 [inline]
 copy_page_from_iter_atomic+0x12f1/0x2b70 lib/iov_iter.c:500
 generic_perform_write+0x4ae/0xc40 mm/filemap.c:3926
 shmem_file_write_iter+0x2b5/0x2e0 mm/shmem.c:2895
 do_iter_write+0xceb/0x1340 fs/read_write.c:860
 vfs_iter_write+0x8e/0xe0 fs/read_write.c:901
 lo_write_bvec drivers/block/loop.c:249 [inline]
 lo_write_simple drivers/block/loop.c:271 [inline]
 do_req_filebacked drivers/block/loop.c:495 [inline]
 loop_handle_cmd drivers/block/loop.c:1915 [inline]
 loop_process_work+0x20c3/0x39d0 drivers/block/loop.c:1950
 loop_workfn+0x48/0x60 drivers/block/loop.c:1974
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2700
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2781
 kthread+0x3ed/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Uninit was created at:
 __alloc_pages+0x9a4/0xe00 mm/page_alloc.c:4591
 alloc_pages_mpol+0x62b/0x9d0 mm/mempolicy.c:2133
 alloc_pages mm/mempolicy.c:2204 [inline]
 folio_alloc+0x1da/0x380 mm/mempolicy.c:2211
 filemap_alloc_folio+0xa5/0x430 mm/filemap.c:974
 __filemap_get_folio+0xa5a/0x1760 mm/filemap.c:1918
 pagecache_get_page+0x4a/0x1a0 mm/folio-compat.c:99
 grab_cache_page_write_begin+0x55/0x70 mm/folio-compat.c:109
 block_write_begin+0x4f/0x450 fs/buffer.c:2223
 cont_write_begin+0xd5c/0x12f0 fs/buffer.c:2582
 fat_write_begin+0x93/0x270 fs/fat/inode.c:230
 generic_perform_write+0x3f5/0xc40 mm/filemap.c:3918
 __generic_file_write_iter+0x20a/0x460 mm/filemap.c:4013
 generic_file_write_iter+0x103/0x5b0 mm/filemap.c:4039
 __kernel_write_iter+0x329/0x930 fs/read_write.c:517
 dump_emit_page fs/coredump.c:888 [inline]
 dump_user_range+0x593/0xcd0 fs/coredump.c:915
 elf_core_dump+0x59e8/0x5c60 fs/binfmt_elf.c:2077
 do_coredump+0x32c9/0x4920 fs/coredump.c:764
 get_signal+0x2185/0x2d10 kernel/signal.c:2890
 arch_do_signal_or_restart+0x53/0xca0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop+0xe8/0x320 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x163/0x220 kernel/entry/common.c:204
 irqentry_exit_to_user_mode+0xd/0x30 kernel/entry/common.c:309
 irqentry_exit+0x16/0x40 kernel/entry/common.c:412
 exc_page_fault+0x246/0x6f0 arch/x86/mm/fault.c:1564
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:570

CPU: 0 PID: 77 Comm: kswapd0 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
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