=====================================================
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0x1c9/0x270 lib/usercopy.c:33
 instrument_copy_to_user include/linux/instrumented.h:121 [inline]
 _copy_to_user+0x1c9/0x270 lib/usercopy.c:33
 copy_to_user include/linux/uaccess.h:209 [inline]
 fb_read+0xa42/0xc80 drivers/video/fbdev/core/fbmem.c:812
 do_iter_read+0xeb9/0x14c0 fs/read_write.c:788
 vfs_readv fs/read_write.c:906 [inline]
 do_preadv+0x45e/0x6c0 fs/read_write.c:998
 __do_compat_sys_preadv fs/read_write.c:1104 [inline]
 __se_compat_sys_preadv fs/read_write.c:1098 [inline]
 __ia32_compat_sys_preadv+0x166/0x1c0 fs/read_write.c:1098
 do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline]
 __do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180
 do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:524 [inline]
 slab_alloc_node mm/slub.c:3251 [inline]
 slab_alloc mm/slub.c:3259 [inline]
 __kmalloc+0xc3c/0x12d0 mm/slub.c:4437
 kmalloc include/linux/slab.h:595 [inline]
 fb_read+0x72a/0xc80 drivers/video/fbdev/core/fbmem.c:795
 do_iter_read+0xeb9/0x14c0 fs/read_write.c:788
 vfs_readv fs/read_write.c:906 [inline]
 do_preadv+0x45e/0x6c0 fs/read_write.c:998
 __do_compat_sys_preadv fs/read_write.c:1104 [inline]
 __se_compat_sys_preadv fs/read_write.c:1098 [inline]
 __ia32_compat_sys_preadv+0x166/0x1c0 fs/read_write.c:1098
 do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline]
 __do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180
 do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Bytes 0-127 of 128 are uninitialized
Memory access of size 128 starts at ffff88808881cf00
Data copied to user address 0000000020000300

CPU: 0 PID: 27255 Comm: syz-executor.2 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
=====================================================