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BUG: KMSAN: kernel-infoleak-after-free in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak-after-free in _inline_copy_to_user include/linux/uaccess.h:196 [inline]
BUG: KMSAN: kernel-infoleak-after-free in _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 _inline_copy_to_user include/linux/uaccess.h:196 [inline]
 _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 copy_siginfo_to_user+0x3f/0x140 kernel/signal.c:3503
 x64_setup_rt_frame+0x1392/0x2590 arch/x86/kernel/signal_64.c:194
 setup_rt_frame arch/x86/kernel/signal.c:250 [inline]
 handle_signal arch/x86/kernel/signal.c:294 [inline]
 arch_do_signal_or_restart+0x5ca/0xbe0 arch/x86/kernel/signal.c:339
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x6c/0xb0 kernel/entry/common.c:218
 do_syscall_64+0xe6/0x1b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 copy_siginfo include/linux/signal.h:18 [inline]
 collect_signal kernel/signal.c:575 [inline]
 __dequeue_signal+0x4d6/0x970 kernel/signal.c:609
 dequeue_signal+0x1c0/0x840 kernel/signal.c:632
 get_signal+0xbf8/0x2a20 kernel/signal.c:2914
 arch_do_signal_or_restart+0x53/0xbe0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x6c/0xb0 kernel/entry/common.c:218
 do_syscall_64+0xe6/0x1b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_free_hook mm/slub.c:2306 [inline]
 slab_free mm/slub.c:4642 [inline]
 kmem_cache_free+0x286/0xf00 mm/slub.c:4744
 __sigqueue_free+0x23a/0x270 kernel/signal.c:475
 flush_sigqueue+0x1c5/0x3f0 kernel/signal.c:486
 release_task+0x2875/0x2af0 kernel/exit.c:299
 wait_task_zombie kernel/exit.c:1264 [inline]
 wait_consider_task+0x28e0/0x3df0 kernel/exit.c:1491
 do_wait_pid kernel/exit.c:1630 [inline]
 __do_wait+0x8fe/0xdd0 kernel/exit.c:1665
 do_wait+0x10e/0x480 kernel/exit.c:1706
 kernel_wait+0xd2/0x290 kernel/exit.c:1882
 call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
 call_usermodehelper_exec_work+0x170/0x300 kernel/umh.c:163
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xb97/0x1d90 kernel/workqueue.c:3319
 worker_thread+0xedf/0x1590 kernel/workqueue.c:3400
 kthread+0xd59/0xf00 kernel/kthread.c:464
 ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Bytes 12-15 of 48 are uninitialized
Memory access of size 48 starts at ffff88812a193e18
Data copied to user address 00007fe07d2a8bb0

CPU: 1 UID: 0 PID: 7353 Comm: syz.4.467 Not tainted 6.15.0-rc6-syzkaller-00173-gf1f2797f8a24 #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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