=====================================================
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:3236 [inline]
 process_scheduled_works+0xb8e/0x1d80 kernel/workqueue.c:3319
 worker_thread+0xedf/0x1590 kernel/workqueue.c:3400
 kthread+0xd59/0xf00 kernel/kthread.c:463
 ret_from_fork+0x1e3/0x310 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:5171
 alloc_pages_mpol+0x328/0x860 mm/mempolicy.c:2416
 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
 alloc_pages_noprof+0x102/0x280 mm/mempolicy.c:2507
 __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_extent fs/bcachefs/io_read.h:147 [inline]
 bchfs_read+0x3ccb/0x4800 fs/bcachefs/fs-io-buffered.c:226
 bch2_readahead+0x1579/0x1c10 fs/bcachefs/fs-io-buffered.c:316
 read_pages+0x15c/0xe30 mm/readahead.c:160
 page_cache_ra_order+0xdc7/0x13f0 mm/readahead.c:512
 page_cache_sync_ra+0x10ac/0x1410 mm/readahead.c:619
 filemap_get_pages+0xfb3/0x3a60 mm/filemap.c:2603
 filemap_read+0x5d2/0x2300 mm/filemap.c:2712
 bch2_read_iter+0x559/0x21b0 fs/bcachefs/fs-io-direct.c:222
 __kernel_read+0x7de/0xe20 fs/read_write.c:530
 kernel_read+0xcb/0x100 fs/read_write.c:548
 prepare_binprm fs/exec.c:1609 [inline]
 search_binary_handler fs/exec.c:1656 [inline]
 exec_binprm fs/exec.c:1702 [inline]
 bprm_execve+0x987/0x18e0 fs/exec.c:1754
 do_execveat_common+0xcaa/0xdf0 fs/exec.c:1860
 do_execveat fs/exec.c:1945 [inline]
 __do_sys_execveat fs/exec.c:2019 [inline]
 __se_sys_execveat fs/exec.c:2013 [inline]
 __x64_sys_execveat+0x144/0x1e0 fs/exec.c:2013
 x64_sys_call+0x2671/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:323
 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: 1140 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound __bch2_read_endio
=====================================================