From: Simon Horman <horms@kernel.org>
To: Long Li <longli@microsoft.com>
Cc: Konstantin Taranov <kotaranov@microsoft.com>,
Jakub Kicinski <kuba@kernel.org>,
"David S . Miller" <davem@davemloft.net>,
Paolo Abeni <pabeni@redhat.com>,
Eric Dumazet <edumazet@google.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
Jason Gunthorpe <jgg@ziepe.ca>, Leon Romanovsky <leon@kernel.org>,
Haiyang Zhang <haiyangz@microsoft.com>,
"K . Y . Srinivasan" <kys@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
shradhagupta@linux.microsoft.com, ernis@linux.microsoft.com,
stephen@networkplumber.org, netdev@vger.kernel.org,
linux-rdma@vger.kernel.org, linux-hyperv@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] net: mana: Cap MSI-X vectors to the device MSI-X table size
Date: Mon, 24 Aug 2026 17:16:58 +0100 [thread overview]
Message-ID: <20260824161658.GY265046@horms.kernel.org> (raw)
In-Reply-To: <20260821183736.733296-1-longli@microsoft.com>
On Fri, Aug 21, 2026 at 11:37:36AM -0700, Long Li wrote:
> mana_gd_query_max_resources() sizes gc->num_msix_usable from resp.max_msix
> and the CPU count, but never from the device MSI-X table. On a 1792 vCPU
> M-series VM that yields 1793 while the table has 1024 entries, and
> mana_gd_setup_remaining_irqs() then walks indices 1..1792, running off the
> end of the region mapped by msix_map_region():
>
> BUG: unable to handle page fault for address: ff8e347f8b99800c
> RIP: 0010:msix_prepare_msi_desc+0x7a/0x90
> RAX: 0000000000004000 RBX: ff4330cb164ea780 RCX: ff8e347f8b998000
> Call Trace:
> <TASK>
> __msi_domain_alloc_irqs+0x13a/0x440
> msi_domain_alloc_irq_at+0x149/0x1b0
> mana_gd_setup+0x351/0x890
> mana_gd_probe+0x274/0x390
> </TASK>
>
> RAX is index 1024 * PCI_MSIX_ENTRY_SIZE, one entry past the table.
>
> msi_insert_desc() does range check the index, but only against the MSI
> domain hwsize, which matches the table only for devices on an MSI parent
> domain. With a global PCI/MSI domain hwsize is MSI_XA_DOMAIN_SIZE, so
> nothing bounds the request.
>
> Cap num_msix_usable with pci_msix_vec_count().
>
> Fixes: 755391121038 ("net: mana: Allocate MSI-X vectors dynamically")
> Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
next prev parent reply other threads:[~2026-08-24 16:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-21 18:37 Long Li
2026-08-24 16:16 ` Simon Horman [this message]
2026-08-24 19:10 ` patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260824161658.GY265046@horms.kernel.org \
--to=horms@kernel.org \
--cc=andrew+netdev@lunn.ch \
--cc=davem@davemloft.net \
--cc=decui@microsoft.com \
--cc=edumazet@google.com \
--cc=ernis@linux.microsoft.com \
--cc=haiyangz@microsoft.com \
--cc=jgg@ziepe.ca \
--cc=kotaranov@microsoft.com \
--cc=kuba@kernel.org \
--cc=kys@microsoft.com \
--cc=leon@kernel.org \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
--cc=longli@microsoft.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=shradhagupta@linux.microsoft.com \
--cc=stephen@networkplumber.org \
--cc=wei.liu@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®