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+0x737/0x1050 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+0xa84/0xb20 mm/swap_state.c:667
 swapin_readahead+0x21a/0x19a0 mm/swap_state.c:820
 do_swap_page+0xfbe/0xb0e0 mm/memory.c:4756
 handle_pte_fault mm/memory.c:6279 [inline]
 __handle_mm_fault mm/memory.c:6414 [inline]
 handle_mm_fault+0x3036/0x6e90 mm/memory.c:6583
 do_user_addr_fault+0x1760/0x2520 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x70/0xb0 arch/x86/mm/fault.c:1527
 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+0x737/0x1050 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+0xa84/0xb20 mm/swap_state.c:667
 swapin_readahead+0x21a/0x19a0 mm/swap_state.c:820
 do_swap_page+0xfbe/0xb0e0 mm/memory.c:4756
 handle_pte_fault mm/memory.c:6279 [inline]
 __handle_mm_fault mm/memory.c:6414 [inline]
 handle_mm_fault+0x3036/0x6e90 mm/memory.c:6583
 do_user_addr_fault+0x1760/0x2520 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x70/0xb0 arch/x86/mm/fault.c:1527
 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+0x737/0x1050 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+0xa84/0xb20 mm/swap_state.c:667
 swapin_readahead+0x21a/0x19a0 mm/swap_state.c:820
 do_swap_page+0xfbe/0xb0e0 mm/memory.c:4756
 handle_pte_fault mm/memory.c:6279 [inline]
 __handle_mm_fault mm/memory.c:6414 [inline]
 handle_mm_fault+0x3036/0x6e90 mm/memory.c:6583
 do_user_addr_fault+0x1760/0x2520 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x70/0xb0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:618

Uninit was stored to memory at:
 memcpy_from_page include/linux/highmem.h:446 [inline]
 zs_obj_read_begin+0x429/0x840 mm/zsmalloc.c:1102
 zswap_decompress+0x1b2/0x1050 mm/zswap.c:942
 zswap_load+0x262/0x570 mm/zswap.c:1627
 swap_read_folio+0x662/0x3050 mm/page_io.c:637
 swap_cluster_readahead+0xa84/0xb20 mm/swap_state.c:667
 swapin_readahead+0x21a/0x19a0 mm/swap_state.c:820
 do_swap_page+0xfbe/0xb0e0 mm/memory.c:4756
 handle_pte_fault mm/memory.c:6279 [inline]
 __handle_mm_fault mm/memory.c:6414 [inline]
 handle_mm_fault+0x3036/0x6e90 mm/memory.c:6583
 do_user_addr_fault+0x1760/0x2520 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x70/0xb0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:618

Uninit was created at:
 __alloc_frozen_pages_noprof+0x6df/0xf50 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+0x397/0x1a00 mm/zsmalloc.c:984
 zs_malloc+0x7d3/0x1cc0 mm/zsmalloc.c:1300
 zswap_compress mm/zswap.c:909 [inline]
 zswap_store_page mm/zswap.c:1428 [inline]
 zswap_store+0x2099/0x4b20 mm/zswap.c:1539
 swap_writeout+0x8bd/0x1380 mm/page_io.c:275
 writeout mm/vmscan.c:651 [inline]
 pageout mm/vmscan.c:698 [inline]
 shrink_folio_list+0x5a11/0x7fd0 mm/vmscan.c:1418
 evict_folios+0x9aa3/0xc030 mm/vmscan.c:4711
 try_to_shrink_lruvec+0x1251/0x1750 mm/vmscan.c:4874
 shrink_one+0x4bd/0xbc0 mm/vmscan.c:4919
 shrink_many mm/vmscan.c:4982 [inline]
 lru_gen_shrink_node mm/vmscan.c:5060 [inline]
 shrink_node+0x4505/0x51a0 mm/vmscan.c:6047
 kswapd_shrink_node mm/vmscan.c:6901 [inline]
 balance_pgdat mm/vmscan.c:7084 [inline]
 kswapd+0x2c29/0x4e20 mm/vmscan.c:7354
 kthread+0xd5a/0xf00 kernel/kthread.c:463
 ret_from_fork+0x207/0x6f0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

CPU: 0 UID: 0 PID: 11287 Comm: syz.4.1220 Tainted: G             L      syzkaller #0 PREEMPT(voluntary) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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