From: Baolu Lu <baolu.lu@linux.intel.com>
To: "Vineeth Pillai (Google)" <vineeth@bitbyteword.org>,
David Woodhouse <dwmw2@infradead.org>
Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/vt-d: debugfs: fix legacy mode page table dump logic
Date: Tue, 16 Sep 2025 12:54:05 +0800 [thread overview]
Message-ID: <3205569f-2870-40ab-bcc8-c99639e501ae@linux.intel.com> (raw)
In-Reply-To: <20250814163026.634182-1-vineeth@bitbyteword.org>
On 8/15/25 00:30, Vineeth Pillai (Google) wrote:
> In legacy mode, SSPTPTR is ignored if TT is not 00b or 01b. SSPTPTR
> maybe uninitialized or zero in that case and may cause oops like:
>
> Oops: general protection fault, probably for non-canonical address 0xf00087d3f000f000: 0000 [#1] SMP NOPTI
> CPU: 2 UID: 0 PID: 786 Comm: cat Not tainted 6.16.0 #191 PREEMPT(voluntary)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-5.fc42 04/01/2014
> RIP: 0010:pgtable_walk_level+0x98/0x150
> RSP: 0018:ffffc90000f279c0 EFLAGS: 00010206
> RAX: 0000000040000000 RBX: ffffc90000f27ab0 RCX: 000000000000001e
> RDX: 0000000000000003 RSI: f00087d3f000f000 RDI: f00087d3f0010000
> RBP: ffffc90000f27a00 R08: ffffc90000f27a98 R09: 0000000000000002
> R10: 0000000000000000 R11: 0000000000000000 R12: f00087d3f000f000
> R13: 0000000000000000 R14: 0000000040000000 R15: ffffc90000f27a98
> FS: 0000764566dcb740(0000)GS:ffff8881f812c000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000764566d44000 CR3: 0000000109d81003 CR4: 0000000000772ef0
> PKRU: 55555554
> Call Trace:
> <TASK>
> pgtable_walk_level+0x88/0x150
> domain_translation_struct_show.isra.0+0x2d9/0x300
> dev_domain_translation_struct_show+0x20/0x40
> seq_read_iter+0x12d/0x490
> ...
>
> Avoid walking the page table if TT is not 00b or 01b.
>
> Signed-off-by: Vineeth Pillai (Google)<vineeth@bitbyteword.org>
> ---
> drivers/iommu/intel/debugfs.c | 17 +++++++++++++++--
> 1 file changed, 15 insertions(+), 2 deletions(-)
Add the fixes tag and queue it for v6.18.
Thanks,
baolu
next prev parent reply other threads:[~2025-09-16 4:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-14 16:30 [PATCH] iommu/vt-d: debugfs: fix legacy mode page table dump logic Vineeth Pillai (Google)
2025-09-16 4:54 ` Baolu Lu [this message]
-- strict thread matches above, loose matches on Subject: below --
2025-08-14 16:31 Vineeth Pillai (Google)
2025-08-15 9:23 ` Tian, Kevin
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