===================================================== BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline] BUG: KMSAN: kernel-infoleak in iterate_iovec include/linux/iov_iter.h:52 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:304 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:330 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x4e4/0x33f0 lib/iov_iter.c:185 instrument_copy_to_user include/linux/instrumented.h:114 [inline] copy_to_user_iter lib/iov_iter.c:24 [inline] iterate_iovec include/linux/iov_iter.h:52 [inline] iterate_and_advance2 include/linux/iov_iter.h:304 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] _copy_to_iter+0x4e4/0x33f0 lib/iov_iter.c:185 copy_page_to_iter+0x482/0x910 lib/iov_iter.c:362 copy_folio_to_iter include/linux/uio.h:204 [inline] hugetlbfs_read_iter+0x6cd/0xe10 fs/hugetlbfs/inode.c:281 do_iter_readv_writev+0x9e1/0xc20 fs/read_write.c:-1 vfs_readv+0x34a/0xf30 fs/read_write.c:1018 do_preadv fs/read_write.c:1132 [inline] __do_sys_preadv fs/read_write.c:1179 [inline] __se_sys_preadv fs/read_write.c:1174 [inline] __x64_sys_preadv+0x2a3/0x510 fs/read_write.c:1174 x64_sys_call+0x3064/0x3e30 arch/x86/include/generated/asm/syscalls_64.h:296 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: __alloc_frozen_pages_noprof+0x689/0xf00 mm/page_alloc.c:5206 alloc_buddy_hugetlb_folio mm/hugetlb.c:1944 [inline] only_alloc_fresh_hugetlb_folio+0x2b0/0x1280 mm/hugetlb.c:1984 alloc_pool_huge_folio+0x60f/0x760 mm/hugetlb.c:2042 set_max_huge_pages mm/hugetlb.c:3912 [inline] __nr_hugepages_store_common+0x609/0x1420 mm/hugetlb.c:4206 hugetlb_sysctl_handler_common mm/hugetlb.c:5129 [inline] hugetlb_sysctl_handler+0x1f7/0x2a0 mm/hugetlb.c:5139 proc_sys_call_handler+0x86b/0xdc0 fs/proc/proc_sysctl.c:600 proc_sys_write+0x3b/0x50 fs/proc/proc_sysctl.c:626 __kernel_write_iter+0x6fa/0xdd0 fs/read_write.c:619 __kernel_write fs/read_write.c:639 [inline] kernel_write+0x322/0x710 fs/read_write.c:660 process_sysctl_arg+0x74b/0x1150 fs/proc/proc_sysctl.c:1687 parse_one kernel/params.c:153 [inline] parse_args+0x652/0x1190 kernel/params.c:186 do_sysctl_args+0xf8/0x210 fs/proc/proc_sysctl.c:1719 kernel_init+0xf7/0x5e0 init/main.c:1506 ret_from_fork+0x1f5/0x4c0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Bytes 0-5 of 6 are uninitialized Memory access of size 6 starts at ffff88811b20000f Data copied to user address 0000200000000080 CPU: 0 UID: 0 PID: 6511 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 =====================================================