syzbot

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BUG: KMSAN: uninit-value in sw842_decompress+0x11f3/0x1780 lib/842/842_decompress.c:303
 sw842_decompress+0x11f3/0x1780 lib/842/842_decompress.c:303
 crypto842_sdecompress+0x46/0x60 crypto/842.c:53
 scomp_acomp_comp_decomp+0xa49/0x1120 include/crypto/internal/scompress.h:-1
 scomp_acomp_decompress+0x30/0x40 crypto/scompress.c:287
 crypto_acomp_decompress+0x5b4/0xe80 crypto/acompress.c:303
 zswap_decompress+0x729/0x1000 mm/zswap.c:967
 zswap_load+0x262/0x570 mm/zswap.c:1627
 swap_read_folio+0x662/0x3050 mm/page_io.c:637
 swap_cluster_readahead+0xa8c/0xb20 mm/swap_state.c:668
 swapin_readahead+0x217/0x1990 mm/swap_state.c:821
 do_swap_page+0x984/0x99b0 mm/memory.c:4753
 handle_pte_fault mm/memory.c:6276 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x3034/0x6ee0 mm/memory.c:6580
 do_user_addr_fault+0x1777/0x2550 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x74/0xc0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:618

Uninit was stored to memory at:
 sw842_decompress+0x11ec/0x1780 lib/842/842_decompress.c:303
 crypto842_sdecompress+0x46/0x60 crypto/842.c:53
 scomp_acomp_comp_decomp+0xa49/0x1120 include/crypto/internal/scompress.h:-1
 scomp_acomp_decompress+0x30/0x40 crypto/scompress.c:287
 crypto_acomp_decompress+0x5b4/0xe80 crypto/acompress.c:303
 zswap_decompress+0x729/0x1000 mm/zswap.c:967
 zswap_load+0x262/0x570 mm/zswap.c:1627
 swap_read_folio+0x662/0x3050 mm/page_io.c:637
 swap_cluster_readahead+0xa8c/0xb20 mm/swap_state.c:668
 swapin_readahead+0x217/0x1990 mm/swap_state.c:821
 do_swap_page+0x984/0x99b0 mm/memory.c:4753
 handle_pte_fault mm/memory.c:6276 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x3034/0x6ee0 mm/memory.c:6580
 do_user_addr_fault+0x1777/0x2550 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x74/0xc0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:618

Uninit was stored to memory at:
 next_bits+0xac2/0xda0 lib/842/842_decompress.c:118
 sw842_decompress+0x1a6/0x1780 lib/842/842_decompress.c:297
 crypto842_sdecompress+0x46/0x60 crypto/842.c:53
 scomp_acomp_comp_decomp+0xa49/0x1120 include/crypto/internal/scompress.h:-1
 scomp_acomp_decompress+0x30/0x40 crypto/scompress.c:287
 crypto_acomp_decompress+0x5b4/0xe80 crypto/acompress.c:303
 zswap_decompress+0x729/0x1000 mm/zswap.c:967
 zswap_load+0x262/0x570 mm/zswap.c:1627
 swap_read_folio+0x662/0x3050 mm/page_io.c:637
 swap_cluster_readahead+0xa8c/0xb20 mm/swap_state.c:668
 swapin_readahead+0x217/0x1990 mm/swap_state.c:821
 do_swap_page+0x984/0x99b0 mm/memory.c:4753
 handle_pte_fault mm/memory.c:6276 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x3034/0x6ee0 mm/memory.c:6580
 do_user_addr_fault+0x1777/0x2550 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x74/0xc0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:618

Uninit was created at:
 __alloc_frozen_pages_noprof+0x421/0xab0 mm/page_alloc.c:5263
 __alloc_pages_noprof+0x41/0xd0 mm/page_alloc.c:5274
 __alloc_pages_node_noprof include/linux/gfp.h:285 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:312 [inline]
 alloc_zpdesc mm/zsmalloc.c:237 [inline]
 alloc_zspage+0x394/0x19f0 mm/zsmalloc.c:984
 zs_malloc+0x79d/0x1250 mm/zsmalloc.c:1300
 zswap_compress mm/zswap.c:909 [inline]
 zswap_store_page mm/zswap.c:1428 [inline]
 zswap_store+0x24a0/0x4a90 mm/zswap.c:1539
 swap_writeout+0x8c1/0x1390 mm/page_io.c:275
 shmem_writeout+0x1abb/0x1f60 mm/shmem.c:1662
 writeout mm/vmscan.c:649 [inline]
 pageout mm/vmscan.c:698 [inline]
 shrink_folio_list+0x5920/0x7fc0 mm/vmscan.c:1418
 evict_folios+0x999d/0xbf30 mm/vmscan.c:4711
 try_to_shrink_lruvec+0x12b6/0x17e0 mm/vmscan.c:4874
 shrink_one+0x43c/0xbd0 mm/vmscan.c:4919
 shrink_many mm/vmscan.c:4982 [inline]
 lru_gen_shrink_node mm/vmscan.c:5060 [inline]
 shrink_node+0x453a/0x51e0 mm/vmscan.c:6047
 shrink_zones mm/vmscan.c:6300 [inline]
 do_try_to_free_pages+0x849/0x26b0 mm/vmscan.c:6362
 try_to_free_pages+0x986/0x16d0 mm/vmscan.c:6608
 __perform_reclaim mm/page_alloc.c:4407 [inline]
 __alloc_pages_direct_reclaim+0x10d/0x340 mm/page_alloc.c:4429
 __alloc_pages_slowpath+0xd30/0x18f0 mm/page_alloc.c:4873
 __alloc_frozen_pages_noprof+0x595/0xab0 mm/page_alloc.c:5253
 __alloc_pages_noprof mm/page_alloc.c:5274 [inline]
 __folio_alloc_noprof+0x48/0x170 mm/page_alloc.c:5284
 alloc_charge_folio+0x6a3/0xb00 mm/khugepaged.c:1071
 collapse_file mm/khugepaged.c:1873 [inline]
 hpage_collapse_scan_file+0x249a/0x9ad0 mm/khugepaged.c:2387
 madvise_collapse+0x6f4/0x1330 mm/khugepaged.c:2810
 madvise_vma_behavior+0x1f52/0x7990 mm/madvise.c:1372
 madvise_walk_vmas+0x83e/0x14c0 mm/madvise.c:1721
 madvise_do_behavior+0x691/0x850 mm/madvise.c:1937
 do_madvise+0x2ad/0x3d0 mm/madvise.c:2030
 __do_sys_madvise mm/madvise.c:2039 [inline]
 __se_sys_madvise mm/madvise.c:2037 [inline]
 __x64_sys_madvise+0xc4/0x140 mm/madvise.c:2037
 x64_sys_call+0x2217/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:29
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 5456 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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