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BUG: KMSAN: uninit-value in iov_iter_alignment_iovec+0x1a8/0x470 lib/iov_iter.c:894
 iov_iter_alignment_iovec+0x1a8/0x470 lib/iov_iter.c:894
 iov_iter_alignment+0x1ac/0x2d0 lib/iov_iter.c:939
 __blockdev_direct_IO+0x170/0x6460 fs/direct-io.c:1121
 blockdev_direct_IO include/linux/fs.h:3280 [inline]
 exfat_direct_IO+0x191/0x900 fs/exfat/inode.c:482
 generic_file_direct_write+0x275/0x6a0 mm/filemap.c:3977
 __generic_file_write_iter+0x242/0x460 mm/filemap.c:4141
 exfat_file_write_iter+0x894/0xfb0 fs/exfat/file.c:598
 io_write+0xd5a/0x2360 io_uring/rw.c:1078
 io_issue_sqe+0x429/0x22c0 io_uring/io_uring.c:1739
 io_queue_sqe io_uring/io_uring.c:1953 [inline]
 io_submit_sqe io_uring/io_uring.c:2209 [inline]
 io_submit_sqes+0x125c/0x2f30 io_uring/io_uring.c:2324
 __do_sys_io_uring_enter io_uring/io_uring.c:3343 [inline]
 __se_sys_io_uring_enter+0x406/0x41c0 io_uring/io_uring.c:3279
 __ia32_sys_io_uring_enter+0x11d/0x1a0 io_uring/io_uring.c:3279
 ia32_sys_call+0x2d8f/0x40d0 arch/x86/include/generated/asm/syscalls_32.h:427
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4091 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 __do_kmalloc_node mm/slub.c:4263 [inline]
 __kmalloc_noprof+0x661/0xf30 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:882 [inline]
 io_alloc_async_data+0xc0/0x220 io_uring/io_uring.c:1650
 io_rw_alloc_async io_uring/rw.c:228 [inline]
 io_prep_rw_setup io_uring/rw.c:245 [inline]
 io_prep_rw+0x921/0xcd0 io_uring/rw.c:286
 io_prep_rwv+0xb3/0x510 io_uring/rw.c:305
 io_prep_writev+0x3a/0x50 io_uring/rw.c:325
 io_init_req io_uring/io_uring.c:2124 [inline]
 io_submit_sqe io_uring/io_uring.c:2171 [inline]
 io_submit_sqes+0x112e/0x2f30 io_uring/io_uring.c:2324
 __do_sys_io_uring_enter io_uring/io_uring.c:3343 [inline]
 __se_sys_io_uring_enter+0x406/0x41c0 io_uring/io_uring.c:3279
 __ia32_sys_io_uring_enter+0x11d/0x1a0 io_uring/io_uring.c:3279
 ia32_sys_call+0x2d8f/0x40d0 arch/x86/include/generated/asm/syscalls_32.h:427
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

CPU: 1 UID: 0 PID: 10694 Comm: syz.2.1258 Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
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