| Message ID | ZSRXXvWMMkm7qqRW@work |
|---|---|
| State | New |
| Headers | show |
| Series | [next] hostap: Add __counted_by for struct prism2_download_data and use struct_size() | expand |
On Mon, Oct 09, 2023 at 01:41:18PM -0600, Gustavo A. R. Silva wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for > array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > While there, use struct_size() helper, instead of the open-coded > version, to calculate the size for the allocation of the whole > flexible structure, including of course, the flexible-array member. > > This code was found with the help of Coccinelle, and audited and > fixed manually. > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > --- > drivers/net/wireless/intersil/hostap/hostap_download.c | 3 +-- > drivers/net/wireless/intersil/hostap/hostap_wlan.h | 2 +- > 2 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/wireless/intersil/hostap/hostap_download.c b/drivers/net/wireless/intersil/hostap/hostap_download.c > index 3672291ced5c..5e5bada28b5b 100644 > --- a/drivers/net/wireless/intersil/hostap/hostap_download.c > +++ b/drivers/net/wireless/intersil/hostap/hostap_download.c > @@ -732,8 +732,7 @@ static int prism2_download(local_info_t *local, > goto out; > } > > - dl = kzalloc(sizeof(*dl) + param->num_areas * > - sizeof(struct prism2_download_data_area), GFP_KERNEL); > + dl = kzalloc(struct_size(dl, data, param->num_areas), GFP_KERNEL); > if (dl == NULL) { > ret = -ENOMEM; > goto out; > diff --git a/drivers/net/wireless/intersil/hostap/hostap_wlan.h b/drivers/net/wireless/intersil/hostap/hostap_wlan.h > index c25cd21d18bd..f71c0545c0be 100644 > --- a/drivers/net/wireless/intersil/hostap/hostap_wlan.h > +++ b/drivers/net/wireless/intersil/hostap/hostap_wlan.h > @@ -617,7 +617,7 @@ struct prism2_download_data { > u32 addr; /* wlan card address */ > u32 len; > u8 *data; /* allocated data */ > - } data[]; > + } data[] __counted_by(num_areas); > }; Should this be considered a v2 of: https://lore.kernel.org/linux-hardening/94848cc3-6f5c-46d7-8cc7-98a4f10865b3@embeddedor.com/ ? Yours is more complete since it includes the struct_size() change...
On Mon, Oct 09, 2023 at 02:33:01PM -0600, Gustavo A. R. Silva wrote: > > > On 10/9/23 21:54, Kees Cook wrote: > > On Mon, Oct 09, 2023 at 01:41:18PM -0600, Gustavo A. R. Silva wrote: > > > Prepare for the coming implementation by GCC and Clang of the __counted_by > > > attribute. Flexible array members annotated with __counted_by can have > > > their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for > > > array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > > > functions). > > > > > > While there, use struct_size() helper, instead of the open-coded > > > version, to calculate the size for the allocation of the whole > > > flexible structure, including of course, the flexible-array member. > > > > > > This code was found with the help of Coccinelle, and audited and > > > fixed manually. > > > > > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > > > --- > > > drivers/net/wireless/intersil/hostap/hostap_download.c | 3 +-- > > > drivers/net/wireless/intersil/hostap/hostap_wlan.h | 2 +- > > > 2 files changed, 2 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/net/wireless/intersil/hostap/hostap_download.c b/drivers/net/wireless/intersil/hostap/hostap_download.c > > > index 3672291ced5c..5e5bada28b5b 100644 > > > --- a/drivers/net/wireless/intersil/hostap/hostap_download.c > > > +++ b/drivers/net/wireless/intersil/hostap/hostap_download.c > > > @@ -732,8 +732,7 @@ static int prism2_download(local_info_t *local, > > > goto out; > > > } > > > - dl = kzalloc(sizeof(*dl) + param->num_areas * > > > - sizeof(struct prism2_download_data_area), GFP_KERNEL); > > > + dl = kzalloc(struct_size(dl, data, param->num_areas), GFP_KERNEL); > > > if (dl == NULL) { > > > ret = -ENOMEM; > > > goto out; > > > diff --git a/drivers/net/wireless/intersil/hostap/hostap_wlan.h b/drivers/net/wireless/intersil/hostap/hostap_wlan.h > > > index c25cd21d18bd..f71c0545c0be 100644 > > > --- a/drivers/net/wireless/intersil/hostap/hostap_wlan.h > > > +++ b/drivers/net/wireless/intersil/hostap/hostap_wlan.h > > > @@ -617,7 +617,7 @@ struct prism2_download_data { > > > u32 addr; /* wlan card address */ > > > u32 len; > > > u8 *data; /* allocated data */ > > > - } data[]; > > > + } data[] __counted_by(num_areas); > > > }; > > > > Should this be considered a v2 of: > > https://lore.kernel.org/linux-hardening/94848cc3-6f5c-46d7-8cc7-98a4f10865b3@embeddedor.com/ > > > > ? > > Oops... sorry, I forgot I had reviewed this patch of yours. > > > > > Yours is more complete since it includes the struct_size() change... > > > > Should I resend this explicitly marking it as a v2? I defer to Kalle -- your Subject is more accurate, so perhaps let's just let this stand?
Kees Cook <keescook@chromium.org> writes: >> > Should this be considered a v2 of: >> > https://lore.kernel.org/linux-hardening/94848cc3-6f5c-46d7-8cc7-98a4f10865b3@embeddedor.com/ >> > >> > ? >> >> Oops... sorry, I forgot I had reviewed this patch of yours. >> >> > >> > Yours is more complete since it includes the struct_size() change... >> > >> >> Should I resend this explicitly marking it as a v2? > > I defer to Kalle -- your Subject is more accurate, so perhaps let's just > let this stand? No need to resend. I marked Kees' version as Superseded so that I don't accidentally take the wrong version. In the title "wifi:" is missing but I can add that during commit.
On 10/10/23 08:17, Kalle Valo wrote: > > No need to resend. I marked Kees' version as Superseded so that I don't > accidentally take the wrong version. > > In the title "wifi:" is missing but I can add that during commit. > Awesome. :) Thanks, Kalle! -- Gustavo
On Mon, Oct 09, 2023 at 01:41:18PM -0600, Gustavo A. R. Silva wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for > array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > While there, use struct_size() helper, instead of the open-coded > version, to calculate the size for the allocation of the whole > flexible structure, including of course, the flexible-array member. > > This code was found with the help of Coccinelle, and audited and > fixed manually. > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> I realize I didn't actually send my R-b for this thread, so here it is: Reviewed-by: Kees Cook <keescook@chromium.org> :)
diff --git a/drivers/net/wireless/intersil/hostap/hostap_download.c b/drivers/net/wireless/intersil/hostap/hostap_download.c index 3672291ced5c..5e5bada28b5b 100644 --- a/drivers/net/wireless/intersil/hostap/hostap_download.c +++ b/drivers/net/wireless/intersil/hostap/hostap_download.c @@ -732,8 +732,7 @@ static int prism2_download(local_info_t *local, goto out; } - dl = kzalloc(sizeof(*dl) + param->num_areas * - sizeof(struct prism2_download_data_area), GFP_KERNEL); + dl = kzalloc(struct_size(dl, data, param->num_areas), GFP_KERNEL); if (dl == NULL) { ret = -ENOMEM; goto out; diff --git a/drivers/net/wireless/intersil/hostap/hostap_wlan.h b/drivers/net/wireless/intersil/hostap/hostap_wlan.h index c25cd21d18bd..f71c0545c0be 100644 --- a/drivers/net/wireless/intersil/hostap/hostap_wlan.h +++ b/drivers/net/wireless/intersil/hostap/hostap_wlan.h @@ -617,7 +617,7 @@ struct prism2_download_data { u32 addr; /* wlan card address */ u32 len; u8 *data; /* allocated data */ - } data[]; + } data[] __counted_by(num_areas); };
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). While there, use struct_size() helper, instead of the open-coded version, to calculate the size for the allocation of the whole flexible structure, including of course, the flexible-array member. This code was found with the help of Coccinelle, and audited and fixed manually. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/net/wireless/intersil/hostap/hostap_download.c | 3 +-- drivers/net/wireless/intersil/hostap/hostap_wlan.h | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-)