Kernel bug: KMSAN: uninit-value in bch2_trans_start_alloc_update
Subsystem: bcachefs
Status: fixed

Crash report:
=====================================================
BUG: KMSAN: uninit-value in bch2_alloc_to_v4_mut_inlined fs/bcachefs/alloc_background.c:447 [inline]
BUG: KMSAN: uninit-value in bch2_trans_start_alloc_update_noupdate fs/bcachefs/alloc_background.c:472 [inline]
BUG: KMSAN: uninit-value in bch2_trans_start_alloc_update+0x674/0x14b0 fs/bcachefs/alloc_background.c:487
 bch2_alloc_to_v4_mut_inlined fs/bcachefs/alloc_background.c:447 [inline]
 bch2_trans_start_alloc_update_noupdate fs/bcachefs/alloc_background.c:472 [inline]
 bch2_trans_start_alloc_update+0x674/0x14b0 fs/bcachefs/alloc_background.c:487
 bch2_trigger_pointer fs/bcachefs/buckets.c:588 [inline]
 __trigger_extent+0x2425/0x6810 fs/bcachefs/buckets.c:740
 bch2_trigger_extent+0x90e/0x11a0 fs/bcachefs/buckets.c:869
 bch2_key_trigger fs/bcachefs/bkey_methods.h:87 [inline]
 bch2_key_trigger_old fs/bcachefs/bkey_methods.h:101 [inline]
 btree_update_nodes_written_trans fs/bcachefs/btree_update_interior.c:651 [inline]
 btree_update_nodes_written fs/bcachefs/btree_update_interior.c:723 [inline]
 btree_interior_update_work+0x1661/0x4870 fs/bcachefs/btree_update_interior.c:861
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
 kthread+0x3e2/0x540 kernel/kthread.c:389
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was stored to memory at:
 memcpy_u64s_small fs/bcachefs/util.h:393 [inline]
 bkey_reassemble fs/bcachefs/bkey.h:513 [inline]
 btree_key_cache_create fs/bcachefs/btree_key_cache.c:259 [inline]
 btree_key_cache_fill+0x13da/0x3d60 fs/bcachefs/btree_key_cache.c:309
 bch2_btree_path_traverse_cached+0x988/0xe20 fs/bcachefs/btree_key_cache.c:361
 bch2_btree_path_traverse_one+0x749/0x47b0 fs/bcachefs/btree_iter.c:1159
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 bch2_btree_iter_peek_slot+0x10b7/0x3950 fs/bcachefs/btree_iter.c:2629
 __bch2_bkey_get_iter fs/bcachefs/btree_iter.h:575 [inline]
 bch2_bkey_get_iter fs/bcachefs/btree_iter.h:589 [inline]
 bch2_trans_start_alloc_update_noupdate fs/bcachefs/alloc_background.c:464 [inline]
 bch2_trans_start_alloc_update+0x3d8/0x14b0 fs/bcachefs/alloc_background.c:487
 bch2_trigger_pointer fs/bcachefs/buckets.c:588 [inline]
 __trigger_extent+0x2425/0x6810 fs/bcachefs/buckets.c:740
 bch2_trigger_extent+0x90e/0x11a0 fs/bcachefs/buckets.c:869
 bch2_key_trigger fs/bcachefs/bkey_methods.h:87 [inline]
 bch2_key_trigger_old fs/bcachefs/bkey_methods.h:101 [inline]
 btree_update_nodes_written_trans fs/bcachefs/btree_update_interior.c:651 [inline]
 btree_update_nodes_written fs/bcachefs/btree_update_interior.c:723 [inline]
 btree_interior_update_work+0x1661/0x4870 fs/bcachefs/btree_update_interior.c:861
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
 kthread+0x3e2/0x540 kernel/kthread.c:389
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was created at:
 ___kmalloc_large_node+0x22c/0x370 mm/slub.c:4219
 __kmalloc_large_node_noprof+0x3f/0x1e0 mm/slub.c:4236
 __do_kmalloc_node mm/slub.c:4252 [inline]
 __kmalloc_node_noprof+0x9d6/0xf50 mm/slub.c:4270
 __kvmalloc_node_noprof+0xc0/0x2d0 mm/util.c:658
 btree_node_data_alloc fs/bcachefs/btree_cache.c:153 [inline]
 __bch2_btree_node_mem_alloc+0x2be/0xa80 fs/bcachefs/btree_cache.c:198
 bch2_fs_btree_cache_init+0x4e4/0xb50 fs/bcachefs/btree_cache.c:653
 bch2_fs_alloc fs/bcachefs/super.c:917 [inline]
 bch2_fs_open+0x4d3a/0x5b40 fs/bcachefs/super.c:2065
 bch2_fs_get_tree+0x983/0x22d0 fs/bcachefs/fs.c:2157
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3507
 path_mount+0x742/0x1f10 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x722/0x810 fs/namespace.c:4034
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4034
 x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166
 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: 75 Comm: kworker/u8:5 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: btree_update btree_interior_update_work
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