=====================================================
BUG: KMSAN: uninit-value in LZ4_decompress_generic lib/lz4/lz4_decompress.c:147 [inline]
BUG: KMSAN: uninit-value in LZ4_decompress_safe_partial+0x825/0x1e50 lib/lz4/lz4_decompress.c:472
 LZ4_decompress_generic lib/lz4/lz4_decompress.c:147 [inline]
 LZ4_decompress_safe_partial+0x825/0x1e50 lib/lz4/lz4_decompress.c:472
 __bio_uncompress+0x641/0xd40 fs/bcachefs/compress.c:200
 bch2_bio_uncompress+0x4d9/0x800 fs/bcachefs/compress.c:330
 __bch2_read_endio+0x16b2/0x25a0 fs/bcachefs/io_read.c:727
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xc1a/0x1e80 kernel/workqueue.c:3317
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3398
 kthread+0x6b9/0xef0 kernel/kthread.c:464
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was created at:
 __alloc_frozen_pages_noprof+0x9a7/0xe00 mm/page_alloc.c:4762
 alloc_pages_mpol+0x4cd/0x890 mm/mempolicy.c:2270
 alloc_frozen_pages_noprof mm/mempolicy.c:2341 [inline]
 alloc_pages_noprof+0x1b5/0x250 mm/mempolicy.c:2361
 __bio_alloc_page_pool fs/bcachefs/io_write.c:113 [inline]
 bch2_bio_alloc_pages_pool+0xc2/0x2d0 fs/bcachefs/io_write.c:134
 __bch2_read_extent+0x3594/0x6c00 fs/bcachefs/io_read.c:1040
 bch2_read_extent fs/bcachefs/io_read.h:134 [inline]
 bchfs_read+0x3af5/0x4240 fs/bcachefs/fs-io-buffered.c:218
 bch2_read_single_folio+0x6b8/0x9a0 fs/bcachefs/fs-io-buffered.c:335
 __bch2_truncate_folio+0x1b1c/0x3030 fs/bcachefs/fs-io.c:314
 bch2_truncate_folio fs/bcachefs/fs-io.c:376 [inline]
 bchfs_truncate+0x8cb/0x1490 fs/bcachefs/fs-io.c:466
 bch2_setattr+0x29f/0x2f0 fs/bcachefs/fs.c:1199
 notify_change+0x1a8e/0x1b80 fs/attr.c:552
 do_truncate+0x22a/0x2b0 fs/open.c:65
 vfs_truncate+0x856/0x900 fs/open.c:115
 do_sys_truncate+0x104/0x240 fs/open.c:138
 __do_sys_truncate fs/open.c:150 [inline]
 __se_sys_truncate fs/open.c:148 [inline]
 __x64_sys_truncate+0x6c/0xa0 fs/open.c:148
 x64_sys_call+0x2e19/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:77
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 50 Comm: kworker/u8:3 Not tainted 6.14.0-rc3-syzkaller-00293-g5cf80612d3f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound __bch2_read_endio
=====================================================