From: Jason Gunthorpe <jgg@ziepe.ca>
To: Yi Liu <yi.l.liu@intel.com>
Cc: syzbot <syzbot+57fdb0cf6a0c5d1f15a2@syzkaller.appspotmail.com>,
iommu@lists.linux.dev, joro@8bytes.org, kevin.tian@intel.com,
linux-kernel@vger.kernel.org, robin.murphy@arm.com,
syzkaller-bugs@googlegroups.com, will@kernel.org
Subject: Re: [syzbot] [iommu?] WARNING in iopt_map_pages (3)
Date: Fri, 12 Dec 2025 02:56:01 -0400 [thread overview]
Message-ID: <aTu8gZcXUY/aidgr@ziepe.ca> (raw)
In-Reply-To: <695e0955-0de4-4059-aa77-66c54669f1a6@intel.com>
On Tue, Dec 09, 2025 at 07:57:06PM +0800, Yi Liu wrote:
> It looks to be an overflow error as user gives the below arg. But
> this should be expected. no?
>
> // start: int64 = 0x1000005 (8 bytes)
> // length: int64 = 0xffffffffffefffff (8 bytes)
Something probably overflowed, the test is:
r0 = openat$iommufd(0xffffffffffffff9c, &(0x7f0000000000), 0x0, 0x0)
ioctl$IOMMU_IOAS_ALLOC(r0, 0x3b81, &(0x7f0000000100)={0xc, 0x0, <r1=>0x0})
ioctl$IOMMU_TEST_OP_ADD_RESERVED(r0, 0x3ba0, &(0x7f0000000040)={0x48, 0x1, r1, 0x0, 0x1000005, 0xffffffffffefffff})
ioctl$IOMMU_TEST_OP_MOCK_DOMAIN_FLAGS(r0, 0x3ba0, &(0x7f00000003c0)={0x48, 0x2, r1})
ioctl$IOMMU_IOAS_MAP$PAGES(r0, 0x3b85, &(0x7f0000001340)={0x28, 0x2, r1, 0x0, &(0x7f00003bd000/0x3000)=nil, 0x3000, 0x80})
And I'm guessing the allocator picked something that failed the
reserved range intersection path:
/* No reserved IOVA intersects the range */
if (iopt_reserved_iter_first(iopt, iova, last))
return -EINVAL;
Maybe due to a corrupted range or something.
I'll look next week
Jason
prev parent reply other threads:[~2025-12-12 6:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-08 7:41 [syzbot] [iommu?] WARNING in iopt_map_pages (3) syzbot
2025-12-09 11:57 ` Yi Liu
2025-12-12 6:56 ` Jason Gunthorpe [this message]
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