| Message ID | ZSR0qh5dEV5qoBW4@work (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 2dd3071892202ccaec3c59afc65c5b88357e73c9 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [next] net: wwan: t7xx: Add __counted_by for struct t7xx_fsm_event and use struct_size() | expand |
On Mon, Oct 09, 2023 at 03:46:18PM -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> Looks right to me. Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > drivers/net/wwan/t7xx/t7xx_state_monitor.c | 3 ++- > drivers/net/wwan/t7xx/t7xx_state_monitor.h | 2 +- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.c b/drivers/net/wwan/t7xx/t7xx_state_monitor.c > index 80edb8e75a6a..0bc97430211b 100644 > --- a/drivers/net/wwan/t7xx/t7xx_state_monitor.c > +++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.c > @@ -445,7 +445,8 @@ int t7xx_fsm_append_event(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_event_state ev > return -EINVAL; > } > > - event = kmalloc(sizeof(*event) + length, in_interrupt() ? GFP_ATOMIC : GFP_KERNEL); > + event = kmalloc(struct_size(event, data, length), > + in_interrupt() ? GFP_ATOMIC : GFP_KERNEL); > if (!event) > return -ENOMEM; > > diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.h b/drivers/net/wwan/t7xx/t7xx_state_monitor.h > index b6e76f3903c8..b0b3662ae6d7 100644 > --- a/drivers/net/wwan/t7xx/t7xx_state_monitor.h > +++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.h > @@ -102,7 +102,7 @@ struct t7xx_fsm_event { > struct list_head entry; > enum t7xx_fsm_event_state event_id; > unsigned int length; > - unsigned char data[]; > + unsigned char data[] __counted_by(length); > }; > > struct t7xx_fsm_command { > -- > 2.34.1 > >
Hello: This patch was applied to netdev/net-next.git (main) by David S. Miller <davem@davemloft.net>: On Mon, 9 Oct 2023 15:46:18 -0600 you 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. > > [...] Here is the summary with links: - [next] net: wwan: t7xx: Add __counted_by for struct t7xx_fsm_event and use struct_size() https://git.kernel.org/netdev/net-next/c/2dd307189220 You are awesome, thank you!
diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.c b/drivers/net/wwan/t7xx/t7xx_state_monitor.c index 80edb8e75a6a..0bc97430211b 100644 --- a/drivers/net/wwan/t7xx/t7xx_state_monitor.c +++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.c @@ -445,7 +445,8 @@ int t7xx_fsm_append_event(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_event_state ev return -EINVAL; } - event = kmalloc(sizeof(*event) + length, in_interrupt() ? GFP_ATOMIC : GFP_KERNEL); + event = kmalloc(struct_size(event, data, length), + in_interrupt() ? GFP_ATOMIC : GFP_KERNEL); if (!event) return -ENOMEM; diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.h b/drivers/net/wwan/t7xx/t7xx_state_monitor.h index b6e76f3903c8..b0b3662ae6d7 100644 --- a/drivers/net/wwan/t7xx/t7xx_state_monitor.h +++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.h @@ -102,7 +102,7 @@ struct t7xx_fsm_event { struct list_head entry; enum t7xx_fsm_event_state event_id; unsigned int length; - unsigned char data[]; + unsigned char data[] __counted_by(length); }; struct t7xx_fsm_command {
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/wwan/t7xx/t7xx_state_monitor.c | 3 ++- drivers/net/wwan/t7xx/t7xx_state_monitor.h | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)