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BUG: KMSAN: uninit-value in zswap_is_page_same_filled mm/zswap.c:1472 [inline]
BUG: KMSAN: uninit-value in zswap_store+0x1f1c/0x3f00 mm/zswap.c:1573
 zswap_is_page_same_filled mm/zswap.c:1472 [inline]
 zswap_store+0x1f1c/0x3f00 mm/zswap.c:1573
 swap_writepage+0x126/0x4c0 mm/page_io.c:198
 shmem_writepage+0x1824/0x1f70 mm/shmem.c:1518
 pageout mm/vmscan.c:654 [inline]
 shrink_folio_list+0x5617/0x7ad0 mm/vmscan.c:1316
 evict_folios+0xab3a/0xcc50 mm/vmscan.c:4521
 try_to_shrink_lruvec+0x15ac/0x1b20 mm/vmscan.c:4726
 shrink_one+0x66e/0xd70 mm/vmscan.c:4765
 shrink_many mm/vmscan.c:4828 [inline]
 lru_gen_shrink_node mm/vmscan.c:4929 [inline]
 shrink_node+0x4c15/0x58b0 mm/vmscan.c:5888
 kswapd_shrink_node mm/vmscan.c:6693 [inline]
 balance_pgdat mm/vmscan.c:6883 [inline]
 kswapd+0x1df3/0x4260 mm/vmscan.c:7143
 kthread+0x3ed/0x550 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:243

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+0x12f5/0x2b70 lib/iov_iter.c:500
 generic_perform_write+0x4ae/0xc40 mm/filemap.c:3938
 shmem_file_write_iter+0x2b5/0x2e0 mm/shmem.c:2893
 do_iter_readv_writev+0x655/0x7a0
 vfs_iter_write+0x455/0xd00 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:1909 [inline]
 loop_process_work+0x14f9/0x3430 drivers/block/loop.c:1944
 loop_workfn+0x48/0x60 drivers/block/loop.c:1968
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x1132/0x1f40 kernel/workqueue.c:2706
 worker_thread+0xea4/0x1560 kernel/workqueue.c:2787
 kthread+0x3ed/0x550 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:243

Uninit was created at:
 __alloc_pages+0x9a6/0xe00 mm/page_alloc.c:4590
 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:975
 __filemap_get_folio+0x9aa/0x13f0 mm/filemap.c:1919
 pagecache_get_page+0x4a/0x1a0 mm/folio-compat.c:93
 grab_cache_page_write_begin+0x55/0x70 mm/folio-compat.c:103
 block_write_begin+0x4f/0x450 fs/buffer.c:2207
 cont_write_begin+0xd5d/0x12f0 fs/buffer.c:2565
 fat_write_begin+0x93/0x270 fs/fat/inode.c:230
 generic_perform_write+0x3f5/0xc40 mm/filemap.c:3930
 __generic_file_write_iter+0x20a/0x460 mm/filemap.c:4025
 generic_file_write_iter+0x103/0x5b0 mm/filemap.c:4051
 __kernel_write_iter+0x686/0xc30 fs/read_write.c:523
 dump_emit_page fs/coredump.c:888 [inline]
 dump_user_range+0x593/0xcd0 fs/coredump.c:915
 elf_core_dump+0x5294/0x5a40 fs/binfmt_elf.c:2077
 do_coredump+0x32c9/0x4920 fs/coredump.c:764
 get_signal+0x21fa/0x2d80 kernel/signal.c:2879
 arch_do_signal_or_restart+0x53/0xca0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 irqentry_exit_to_user_mode+0xa1/0x150 kernel/entry/common.c:225
 irqentry_exit+0x16/0x50 kernel/entry/common.c:328
 exc_page_fault+0x534/0x720 arch/x86/mm/fault.c:1557
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:570

CPU: 0 PID: 87 Comm: kswapd0 Not tainted 6.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
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