=====================================================
BUG: KMSAN: uninit-value in LZ4_decompress_generic lib/lz4/lz4_decompress.c:147 [inline]
BUG: KMSAN: uninit-value in LZ4_decompress_safe_partial+0x94a/0x2190 lib/lz4/lz4_decompress.c:472
 LZ4_decompress_generic lib/lz4/lz4_decompress.c:147 [inline]
 LZ4_decompress_safe_partial+0x94a/0x2190 lib/lz4/lz4_decompress.c:472
 __bio_uncompress+0x627/0x1490 fs/bcachefs/compress.c:200
 bch2_bio_uncompress+0x507/0x9b0 fs/bcachefs/compress.c:323
 __bch2_read_endio+0x17e4/0x2240 fs/bcachefs/io_read.c:871
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xb91/0x1d80 kernel/workqueue.c:3321
 worker_thread+0xedf/0x1590 kernel/workqueue.c:3402
 kthread+0xd59/0xf00 kernel/kthread.c:464
 ret_from_fork+0x1e0/0x310 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Uninit was created at:
 __alloc_frozen_pages_noprof+0x689/0xf00 mm/page_alloc.c:4982
 alloc_pages_mpol+0x328/0x860 mm/mempolicy.c:2419
 alloc_frozen_pages_noprof mm/mempolicy.c:2490 [inline]
 alloc_pages_noprof+0x102/0x280 mm/mempolicy.c:2510
 __bio_alloc_page_pool fs/bcachefs/io_write.c:121 [inline]
 bch2_bio_alloc_pages_pool+0x8f/0x230 fs/bcachefs/io_write.c:142
 __bch2_read_extent+0x334e/0x6220 fs/bcachefs/io_read.c:1193
 __bch2_read+0x251d/0x39b0 fs/bcachefs/io_read.c:1428
 bch2_read fs/bcachefs/io_read.h:164 [inline]
 bch2_direct_IO_read fs/bcachefs/fs-io-direct.c:172 [inline]
 bch2_read_iter+0x14e4/0x21b0 fs/bcachefs/fs-io-direct.c:215
 copy_splice_read+0xa2d/0x1120 fs/splice.c:363
 do_splice_read fs/splice.c:978 [inline]
 splice_direct_to_actor+0x788/0x1550 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0x1e0/0x350 fs/splice.c:1227
 do_sendfile+0x9eb/0x1110 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64+0x1e3/0x280 fs/read_write.c:1417
 __x64_sys_sendfile64+0xbd/0x120 fs/read_write.c:1417
 x64_sys_call+0xd49/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 9040 Comm: kworker/u8:8 Not tainted 6.16.0-rc6-syzkaller-00253-g4871b7cb27f4 #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound __bch2_read_endio
=====================================================