netdev - Re: [PATCH net v3] net: Clear old fragment checksum value in napi_reuse

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CANn89iJLZ+3-HTQJSsk9iNnXy89uE9oLQn=ZLNayY16hauBYew@mail.gmail.com>
Date: Wed, 26 Feb 2025 05:35:39 +0100
From: Eric Dumazet <edumazet@...gle.com>
To: Mohammad Heib <mheib@...hat.com>
Cc: netdev@...r.kernel.org, davem@...emloft.net, kuba@...nel.org, 
	pabeni@...hat.com
Subject: Re: [PATCH net v3] net: Clear old fragment checksum value in napi_reuse_skb

On Tue, Feb 25, 2025 at 12:29 PM Mohammad Heib <mheib@...hat.com> wrote:
>
> In certain cases, napi_get_frags() returns an skb that points to an old
> received fragment, This skb may have its skb->ip_summed, csum, and other
> fields set from previous fragment handling.
>
> Some network drivers set skb->ip_summed to either CHECKSUM_COMPLETE or
> CHECKSUM_UNNECESSARY when getting skb from napi_get_frags(), while
> others only set skb->ip_summed when RX checksum offload is enabled on
> the device, and do not set any value for skb->ip_summed when hardware
> checksum offload is disabled, assuming that the skb->ip_summed
> initiated to zero by napi_reuse_skb, ionic driver for example will
> ignore/unset any value for the ip_summed filed if HW checksum offload is
> disabled, and if we have a situation where the user disables the
> checksum offload during a traffic that could lead to the following
> errors shown in the kernel logs:

It would be nice if you could get symbols with this trace
( scripts/decode_stacktrace.sh )

> <IRQ>
> dump_stack_lvl+0x34/0x48
>  __skb_gro_checksum_complete+0x7e/0x90
> tcp6_gro_receive+0xc6/0x190
> ipv6_gro_receive+0x1ec/0x430
> dev_gro_receive+0x188/0x360
> ? ionic_rx_clean+0x25a/0x460 [ionic]
> napi_gro_frags+0x13c/0x300
> ? __pfx_ionic_rx_service+0x10/0x10 [ionic]
> ionic_rx_service+0x67/0x80 [ionic]
> ionic_cq_service+0x58/0x90 [ionic]
> ionic_txrx_napi+0x64/0x1b0 [ionic]
>  __napi_poll+0x27/0x170
> net_rx_action+0x29c/0x370
> handle_softirqs+0xce/0x270
> __irq_exit_rcu+0xa3/0xc0
> common_interrupt+0x80/0xa0
> </IRQ>
>

Note : This suggests ionic driver could add one
skb_checksum_none_assert() as other drivers did

Reviewed-by: Eric Dumazet <edumazet@...gle.com>