syzbot


KMSAN: uninit-value in sw842_decompress (2)

Status: upstream: reported on 2025/04/06 12:32
Subsystems: crypto
[Documentation on labels]
Reported-by: syzbot+8f77ff6144a73f0cf71b@syzkaller.appspotmail.com
First crash: 149d, last: 4d18h
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly crypto report (Jul 2025) 0 (1) 2025/07/31 12:52
[syzbot] [crypto?] KMSAN: uninit-value in sw842_decompress (2) 0 (1) 2025/04/06 12:32
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in sw842_decompress crypto 7 1 281d 277d 0/29 auto-obsoleted due to no activity on 2025/03/01 12:04

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in crc32_be_base lib/crc/crc32-main.c:46 [inline]
BUG: KMSAN: uninit-value in crc32_be+0x215/0x270 lib/crc/crc32-main.c:80
 crc32_be_base lib/crc/crc32-main.c:46 [inline]
 crc32_be+0x215/0x270 lib/crc/crc32-main.c:80
 sw842_decompress+0x15c6/0x1780 lib/842/842_decompress.c:385
 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+0x510/0xea0 mm/zswap.c:1032
 zswap_load+0x262/0x570 mm/zswap.c:1689
 swap_read_folio+0x69d/0x3120 mm/page_io.c:637
 swap_cluster_readahead+0xa82/0xb20 mm/swap_state.c:635
 swapin_readahead+0x1d9/0x15b0 mm/swap_state.c:811
 do_swap_page+0xa39/0x9df0 mm/memory.c:4586
 handle_pte_fault mm/memory.c:6055 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x3ff9/0xdf70 mm/memory.c:6364
 do_user_addr_fault+0x177d/0x2560 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x68/0xb0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623

Uninit was created at:
 __alloc_frozen_pages_noprof+0x689/0xf00 mm/page_alloc.c:5171
 alloc_pages_mpol+0x328/0x860 mm/mempolicy.c:2416
 folio_alloc_mpol_noprof+0x56/0x1d0 mm/mempolicy.c:2435
 __read_swap_cache_async+0x2a7/0x980 mm/swap_state.c:400
 swap_cluster_readahead+0x9ff/0xb20 mm/swap_state.c:632
 swapin_readahead+0x1d9/0x15b0 mm/swap_state.c:811
 do_swap_page+0xa39/0x9df0 mm/memory.c:4586
 handle_pte_fault mm/memory.c:6055 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x3ff9/0xdf70 mm/memory.c:6364
 do_user_addr_fault+0x177d/0x2560 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x68/0xb0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623

CPU: 1 UID: 0 PID: 5792 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
=====================================================

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/25 10:49 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/08/18 00:31 upstream 8d561baae505 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/08/12 17:08 upstream 53e760d89498 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/08/07 16:12 upstream 6e64f4580381 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/07/24 06:56 upstream 01a412d06bc5 0c1d6ded .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/07/21 19:18 upstream 89be9a83ccf1 0b3788a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/07/17 06:53 upstream e2291551827f 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/07/14 21:43 upstream 347e9f5043c8 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/07/14 09:28 upstream 5d5d62298b8b 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/07/04 08:42 upstream 17bbde2e1716 76ad128c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/07/02 03:46 upstream 66701750d556 ffe4b334 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/06/28 16:02 upstream 35e261cd95dd fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/05/04 18:23 upstream 02ddfb981de8 b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/04/02 12:25 upstream acc4d5ff0b61 c799dfdd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sw842_decompress
2025/06/27 01:07 upstream e34a79b96ab9 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in sw842_decompress
* Struck through repros no longer work on HEAD.