[syzbot] KMSAN: kernel-infoleak in ucma_init_qp_attr

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 81c325bbf94e kmsan: hooks: do not check memory in kmsan_in..
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=10c4260db00000
kernel config: https://syzkaller.appspot.com/x/.config?x=2d8b9a11641dc9aa
dashboard link: https://syzkaller.appspot.com/bug?extid=6d532fa8f9463da290bc
compiler: clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6d532f...@syzkaller.appspotmail.com

=====================================================
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]
ucma_init_qp_attr+0x8c7/0xb10 drivers/infiniband/core/ucma.c:1242
ucma_write+0x637/0x6c0 drivers/infiniband/core/ucma.c:1732
vfs_write+0x8ce/0x2030 fs/read_write.c:588
ksys_write+0x28b/0x510 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__ia32_sys_write+0xdb/0x120 fs/read_write.c:652
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

Local variable resp created at:
ucma_init_qp_attr+0xa4/0xb10 drivers/infiniband/core/ucma.c:1214
ucma_write+0x637/0x6c0 drivers/infiniband/core/ucma.c:1732

Bytes 40-59 of 144 are uninitialized
Memory access of size 144 starts at ffff888167523b00
Data copied to user address 0000000020000100

CPU: 1 PID: 25910 Comm: syz-executor.1 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
=====================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[Leon Romanovsky]

We are not clearing GRH fields in ib_copy_ah_attr_to_user() if dst->is_global is not set.
I'm testing the fix now and will post the patch after it will pass CI.

Thanks