=====================================================
BUG: KMSAN: uninit-value in __flush_smp_call_function_queue+0x362/0x18e0 kernel/smp.c:535
 __flush_smp_call_function_queue+0x362/0x18e0 kernel/smp.c:535
 generic_smp_call_function_single_interrupt+0x1c/0x30 kernel/smp.c:463
 __sysvec_call_function_single+0x4b/0x3e0 arch/x86/kernel/smp.c:271
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
 sysvec_call_function_single+0x7c/0x90 arch/x86/kernel/smp.c:266
 asm_sysvec_call_function_single+0x1f/0x30 arch/x86/include/asm/idtentry.h:704
 smap_save mm/kmsan/instrumentation.c:92 [inline]
 get_shadow_origin_ptr mm/kmsan/instrumentation.c:35 [inline]
 __msan_metadata_ptr_for_store_2+0x14/0x40 mm/kmsan/instrumentation.c:92
 update_stat drivers/virtio/virtio_balloon.c:341 [inline]
 update_balloon_vm_stats drivers/virtio/virtio_balloon.c:377 [inline]
 update_balloon_stats+0x43c/0x860 drivers/virtio/virtio_balloon.c:403
 stats_handle_request drivers/virtio/virtio_balloon.c:447 [inline]
 update_balloon_stats_func+0xbe/0x300 drivers/virtio/virtio_balloon.c:547
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb82/0x1e80 kernel/workqueue.c:3359
 worker_thread+0xee4/0x1590 kernel/workqueue.c:3440
 kthread+0x53f/0x600 kernel/kthread.c:436
 ret_from_fork+0x20f/0x910 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Uninit was stored to memory at:
 mas_topiary_replace lib/maple_tree.c:2411 [inline]
 mas_wmb_replace+0x369d/0x4260 lib/maple_tree.c:2433
 mas_split lib/maple_tree.c:3052 [inline]
 mas_commit_b_node lib/maple_tree.c:3072 [inline]
 mas_wr_bnode lib/maple_tree.c:3739 [inline]
 mas_wr_store_entry+0x30fe/0x96d0 lib/maple_tree.c:3771
 mas_store_prealloc+0x1834/0x1e60 lib/maple_tree.c:5169
 vma_iter_store_overwrite mm/vma.h:607 [inline]
 vma_iter_store_new mm/vma.h:614 [inline]
 vma_complete+0xbea/0x1950 mm/vma.c:356
 __split_vma+0x120c/0x1330 mm/vma.c:566
 vms_gather_munmap_vmas+0x5e3/0x1ab0 mm/vma.c:1429
 __mmap_setup mm/vma.c:2411 [inline]
 __mmap_region mm/vma.c:2741 [inline]
 mmap_region+0xc9d/0x62b0 mm/vma.c:2844
 do_mmap+0x17aa/0x1d70 mm/mmap.c:559
 vm_mmap_pgoff+0x40c/0x760 mm/util.c:581
 ksys_mmap_pgoff+0x524/0x7d0 mm/mmap.c:605
 __do_sys_mmap_pgoff mm/mmap.c:616 [inline]
 __se_sys_mmap_pgoff mm/mmap.c:612 [inline]
 __ia32_sys_mmap_pgoff+0x11a/0x1d0 mm/mmap.c:612
 ia32_sys_call+0x3743/0x4360 arch/x86/include/generated/asm/syscalls_32.h:193
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x17f/0x3f0 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/syscall_32.c:332
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:370
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Local variable tmp_next.i created at:
 mas_topiary_replace lib/maple_tree.c:2335 [inline]
 mas_wmb_replace+0x66/0x4260 lib/maple_tree.c:2433
 mas_split lib/maple_tree.c:3052 [inline]
 mas_commit_b_node lib/maple_tree.c:3072 [inline]
 mas_wr_bnode lib/maple_tree.c:3739 [inline]
 mas_wr_store_entry+0x30fe/0x96d0 lib/maple_tree.c:3771

CPU: 0 UID: 0 PID: 5832 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_freezable update_balloon_stats_func
=====================================================