From: Kees Cook <keescook@chromium.org>
To: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org>,
linux-wireless <linux-wireless@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 05/32] brcmfmac: Use mem_to_flex_dup() with struct brcmf_fweh_queue_item
Date: Mon, 16 May 2022 20:57:42 -0700 [thread overview]
Message-ID: <202205162056.F8D1BF3E@keescook> (raw)
In-Reply-To: <b197ca6d-4285-5310-7e98-918c885a2e38@broadcom.com>
On Mon, May 16, 2022 at 02:49:21PM +0200, Arend van Spriel wrote:
> On 5/4/2022 3:44 AM, Kees Cook wrote:
> > As part of the work to perform bounds checking on all memcpy() uses,
> > replace the open-coded a deserialization of bytes out of memory into a
> > trailing flexible array by using a flex_array.h helper to perform the
> > allocation, bounds checking, and copying.
> >
> Reviewed-by: Arend van Spriel <aspriel@gmail.com>
Thanks!
> > [...]
> > diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
> > index bc3f4e4edcdf..bea798ca6466 100644
> > --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
> > +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
> > @@ -32,8 +32,8 @@ struct brcmf_fweh_queue_item {
> > u8 ifidx;
> > u8 ifaddr[ETH_ALEN];
> > struct brcmf_event_msg_be emsg;
> > - u32 datalen;
> > - u8 data[];
> > + DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(u32, datalen);
> > + DECLARE_FLEX_ARRAY_ELEMENTS(u8, data);
> > };
> > [...]
> > @@ -414,8 +414,7 @@ void brcmf_fweh_process_event(struct brcmf_pub *drvr,
> > datalen + sizeof(*event_packet) > packet_len)
> > return;
> > - event = kzalloc(sizeof(*event) + datalen, gfp);
> > - if (!event)
> > + if (mem_to_flex_dup(&event, data, datalen, gfp))
> > return;
> > event->code = code;
> > @@ -423,8 +422,6 @@ void brcmf_fweh_process_event(struct brcmf_pub *drvr,
> > /* use memcpy to get aligned event message */
> > memcpy(&event->emsg, &event_packet->msg, sizeof(event->emsg));
> > - memcpy(event->data, data, datalen);
> > - event->datalen = datalen;
>
> So does mem_to_flex_dup() store event->datalen?
>
> Don't have the entire thread so missing bits and pieces, but at least this
> raises questions for me.
Yes, that's part of the internal workings here -- the flex array counter
is declared and will be set as part of the copy.
--
Kees Cook
next prev parent reply other threads:[~2022-05-17 3:57 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-04 1:44 [PATCH 00/32] Introduce flexible array struct memcpy() helpers Kees Cook
2022-05-04 1:44 ` [PATCH 01/32] netlink: Avoid memcpy() across flexible array boundary Kees Cook
2022-05-04 3:31 ` Gustavo A. R. Silva
2022-05-04 3:37 ` Kees Cook
2022-05-04 1:44 ` [PATCH 02/32] Introduce flexible array struct memcpy() helpers Kees Cook
2022-05-04 7:25 ` Johannes Berg
2022-05-04 15:38 ` Kees Cook
2022-05-04 16:08 ` David Laight
2022-05-05 13:16 ` Johannes Berg
2022-05-05 15:16 ` Keith Packard
2022-05-05 19:32 ` Kees Cook
2022-05-05 20:08 ` Keith Packard
2022-05-05 20:12 ` Johannes Berg
2022-05-06 11:15 ` David Laight
2022-05-05 19:27 ` Kees Cook
2022-05-04 1:44 ` [PATCH 03/32] flex_array: Add Kunit tests Kees Cook
2022-05-04 3:00 ` David Gow
2022-05-04 19:43 ` Kees Cook
2022-05-04 19:58 ` Daniel Latypov
2022-05-04 1:44 ` [PATCH 04/32] fortify: Add run-time WARN for cross-field memcpy() Kees Cook
2022-05-04 1:44 ` [PATCH 05/32] brcmfmac: Use mem_to_flex_dup() with struct brcmf_fweh_queue_item Kees Cook
2022-05-16 12:49 ` Arend van Spriel
2022-05-17 3:57 ` Kees Cook [this message]
2022-05-04 1:44 ` [PATCH 06/32] iwlwifi: calib: Prepare to use mem_to_flex_dup() Kees Cook
2022-05-04 1:44 ` [PATCH 07/32] iwlwifi: calib: Use mem_to_flex_dup() with struct iwl_calib_result Kees Cook
2022-05-04 1:44 ` [PATCH 08/32] iwlwifi: mvm: Use mem_to_flex_dup() with struct ieee80211_key_conf Kees Cook
2022-05-04 1:44 ` [PATCH 09/32] p54: Use mem_to_flex_dup() with struct p54_cal_database Kees Cook
2022-05-04 1:44 ` [PATCH 10/32] wcn36xx: Use mem_to_flex_dup() with struct wcn36xx_hal_ind_msg Kees Cook
2022-05-04 5:42 ` Kalle Valo
2022-05-04 15:08 ` Kees Cook
2022-05-04 1:44 ` [PATCH 11/32] nl80211: Use mem_to_flex_dup() with struct cfg80211_cqm_config Kees Cook
2022-05-04 1:44 ` [PATCH 12/32] cfg80211: Use mem_to_flex_dup() with struct cfg80211_bss_ies Kees Cook
2022-05-04 7:28 ` Johannes Berg
2022-05-04 15:13 ` Kees Cook
2022-05-04 1:44 ` [PATCH 13/32] mac80211: Use mem_to_flex_dup() with several structs Kees Cook
2022-05-04 1:44 ` [PATCH 14/32] af_unix: Use mem_to_flex_dup() with struct unix_address Kees Cook
2022-05-04 1:44 ` [PATCH 15/32] 802/garp: Use mem_to_flex_dup() with struct garp_attr Kees Cook
2022-05-04 1:44 ` [PATCH 16/32] 802/mrp: Use mem_to_flex_dup() with struct mrp_attr Kees Cook
2022-05-04 1:44 ` [PATCH 17/32] net/flow_offload: Use mem_to_flex_dup() with struct flow_action_cookie Kees Cook
2022-05-04 1:44 ` [PATCH 18/32] firewire: Use __mem_to_flex_dup() with struct iso_interrupt_event Kees Cook
2022-05-04 1:44 ` [PATCH 19/32] afs: Use mem_to_flex_dup() with struct afs_acl Kees Cook
2022-05-12 21:41 ` David Howells
2022-05-13 15:44 ` Kees Cook
2022-05-04 1:44 ` [PATCH 20/32] ASoC: sigmadsp: Use mem_to_flex_dup() with struct sigmadsp_data Kees Cook
2022-05-04 15:17 ` Mark Brown
2022-05-04 1:44 ` [PATCH 21/32] soc: qcom: apr: Use mem_to_flex_dup() with struct apr_rx_buf Kees Cook
2022-05-04 1:44 ` [PATCH 22/32] atags_proc: Use mem_to_flex_dup() with struct buffer Kees Cook
2022-05-04 1:44 ` [PATCH 23/32] Bluetooth: Use mem_to_flex_dup() with struct hci_op_configure_data_path Kees Cook
2022-05-04 1:44 ` [PATCH 24/32] IB/hfi1: Use mem_to_flex_dup() for struct tid_rb_node Kees Cook
2022-05-04 1:44 ` [PATCH 25/32] Drivers: hv: utils: Use mem_to_flex_dup() with struct cn_msg Kees Cook
2022-05-04 1:44 ` [PATCH 26/32] ima: Use mem_to_flex_dup() with struct modsig Kees Cook
2022-05-04 1:44 ` [PATCH 27/32] KEYS: Use mem_to_flex_dup() with struct user_key_payload Kees Cook
2022-05-04 1:44 ` [PATCH 28/32] selinux: Use mem_to_flex_dup() with xfrm and sidtab Kees Cook
2022-05-04 22:57 ` Paul Moore
2022-05-04 23:43 ` Gustavo A. R. Silva
2022-05-05 3:14 ` Paul Moore
2022-05-05 18:39 ` Kees Cook
2022-05-05 23:16 ` Paul Moore
2022-05-06 1:08 ` Gustavo A. R. Silva
2022-05-04 1:44 ` [PATCH 29/32] xtensa: Use mem_to_flex_dup() with struct property Kees Cook
2022-05-04 18:09 ` Rob Herring
2022-05-04 1:44 ` [PATCH 30/32] usb: gadget: f_fs: Use mem_to_flex_dup() with struct ffs_buffer Kees Cook
2022-05-04 1:44 ` [PATCH 31/32] xenbus: Use mem_to_flex_dup() with struct read_buffer Kees Cook
2022-05-04 1:44 ` [PATCH 32/32] esas2r: Use __mem_to_flex() with struct atto_ioctl Kees Cook
2022-05-12 21:47 ` [PATCH 00/32] Introduce flexible array struct memcpy() helpers David Howells
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