From: syzbot <syzbot+a0c841e02f328005bbcc@syzkaller.appspotmail.com>
To: iommu@lists.linux.dev, jgg@ziepe.ca, joro@8bytes.org,
kevin.tian@intel.com, linux-kernel@vger.kernel.org,
robin.murphy@arm.com, syzkaller-bugs@googlegroups.com,
will@kernel.org
Subject: [syzbot] [iommu?] KMSAN: uninit-value in iopt_pages_unfill_xarray
Date: Sat, 24 Jan 2026 22:02:28 -0800 [thread overview]
Message-ID: <6975b1f4.a00a0220.33ccc7.001f.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 6c790212c588 Merge tag 'devicetree-fixes-for-6.19-3' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=113ef852580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8bf02b9e495b9fcd
dashboard link: https://syzkaller.appspot.com/bug?extid=a0c841e02f328005bbcc
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1796579a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13919d22580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/913c7571d705/disk-6c790212.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/62003bdb5d84/vmlinux-6c790212.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5fd53ea608c6/bzImage-6c790212.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a0c841e02f328005bbcc@syzkaller.appspotmail.com
=====================================================
BUG: KMSAN: uninit-value in batch_add_pfn_num drivers/iommu/iommufd/pages.c:365 [inline]
BUG: KMSAN: uninit-value in batch_add_pfn drivers/iommu/iommufd/pages.c:398 [inline]
BUG: KMSAN: uninit-value in batch_from_xarray_clear drivers/iommu/iommufd/pages.c:590 [inline]
BUG: KMSAN: uninit-value in iopt_pages_unpin_xarray drivers/iommu/iommufd/pages.c:2030 [inline]
BUG: KMSAN: uninit-value in iopt_pages_unfill_xarray+0xfe3/0x1660 drivers/iommu/iommufd/pages.c:2068
batch_add_pfn_num drivers/iommu/iommufd/pages.c:365 [inline]
batch_add_pfn drivers/iommu/iommufd/pages.c:398 [inline]
batch_from_xarray_clear drivers/iommu/iommufd/pages.c:590 [inline]
iopt_pages_unpin_xarray drivers/iommu/iommufd/pages.c:2030 [inline]
iopt_pages_unfill_xarray+0xfe3/0x1660 drivers/iommu/iommufd/pages.c:2068
iopt_area_remove_access+0x508/0x650 drivers/iommu/iommufd/pages.c:2516
iommufd_access_unpin_pages+0x637/0xa50 drivers/iommu/iommufd/device.c:1358
iommufd_test_access_unmap+0x423/0x6b0 drivers/iommu/iommufd/selftest.c:1384
iommufd_test_staccess_release+0x7f/0x140 drivers/iommu/iommufd/selftest.c:1425
__fput+0x60e/0x1050 fs/file_table.c:468
____fput+0x25/0x30 fs/file_table.c:496
task_work_run+0x208/0x2b0 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x2ff/0x1b20 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x1d7/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Local variable batch created at:
iopt_pages_unfill_xarray+0x86/0x1660 drivers/iommu/iommufd/pages.c:2053
iopt_area_remove_access+0x508/0x650 drivers/iommu/iommufd/pages.c:2516
CPU: 0 UID: 0 PID: 6001 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
=====================================================
---
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next reply other threads:[~2026-01-25 6:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-25 6:02 syzbot [this message]
2026-01-26 2:29 ` [syzbot] [iommu?] KMSAN: uninit-value in iopt_pages_unfill_xarray Edward Adam Davis
2026-01-26 3:10 ` syzbot
2026-01-28 16:50 ` Jason Gunthorpe
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