| Message ID | 20210810210741.GA58765@embeddedor |
|---|---|
| State | New |
| Headers | show |
| Series | [next] scsi: smartpqi: Replace one-element array with flexible-array member | expand |
Gustavo, > There is a regular need in the kernel to provide a way to declare > having a dynamically sized set of trailing elements in a > structure. Kernel code should always use “flexible array members”[1] > for these cases. The older style of one-element or zero-length arrays > should no longer be used[2]. Applied to 5.15/scsi-staging, thanks! -- Martin K. Petersen Oracle Linux Engineering
Hi Martin, On 8/16/21 22:01, Martin K. Petersen wrote: > > Gustavo, > >> There is a regular need in the kernel to provide a way to declare >> having a dynamically sized set of trailing elements in a >> structure. Kernel code should always use “flexible array members”[1] >> for these cases. The older style of one-element or zero-length arrays >> should no longer be used[2]. > > Applied to 5.15/scsi-staging, thanks! Thanks for this. :) Could you take this series too, please: https://lore.kernel.org/linux-hardening/cover.1628136510.git.gustavoars@kernel.org/ Thanks! -- Gustavo
On Tue, 10 Aug 2021 16:07:41 -0500, Gustavo A. R. Silva wrote: > There is a regular need in the kernel to provide a way to declare having > a dynamically sized set of trailing elements in a structure. Kernel code > should always use “flexible array members”[1] for these cases. The older > style of one-element or zero-length arrays should no longer be used[2]. > > Refactor the code a bit according to the use of a flexible-array member > in struct pqi_event_config instead of a one-element array, and use the > struct_size() helper. > > [...] Applied to 5.15/scsi-queue, thanks! [1/1] scsi: smartpqi: Replace one-element array with flexible-array member https://git.kernel.org/mkp/scsi/c/5f492a7aa13b -- Martin K. Petersen Oracle Linux Engineering
diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h index f340afc011b5..70eca203d72f 100644 --- a/drivers/scsi/smartpqi/smartpqi.h +++ b/drivers/scsi/smartpqi/smartpqi.h @@ -415,7 +415,7 @@ struct pqi_event_config { u8 reserved[2]; u8 num_event_descriptors; u8 reserved1; - struct pqi_event_descriptor descriptors[1]; + struct pqi_event_descriptor descriptors[]; }; #define PQI_MAX_EVENT_DESCRIPTORS 255 diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c index c1f0f8da9fe2..f9107127bd6e 100644 --- a/drivers/scsi/smartpqi/smartpqi_init.c +++ b/drivers/scsi/smartpqi/smartpqi_init.c @@ -4740,8 +4740,7 @@ static int pqi_create_queues(struct pqi_ctrl_info *ctrl_info) } #define PQI_REPORT_EVENT_CONFIG_BUFFER_LENGTH \ - (offsetof(struct pqi_event_config, descriptors) + \ - (PQI_MAX_EVENT_DESCRIPTORS * sizeof(struct pqi_event_descriptor))) + struct_size((struct pqi_event_config *)0, descriptors, PQI_MAX_EVENT_DESCRIPTORS) static int pqi_configure_events(struct pqi_ctrl_info *ctrl_info, bool enable_events)
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code a bit according to the use of a flexible-array member in struct pqi_event_config instead of a one-element array, and use the struct_size() helper. This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). This issue was found with the help of Coccinelle and audited and fixed, manually. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/scsi/smartpqi/smartpqi.h | 2 +- drivers/scsi/smartpqi/smartpqi_init.c | 3 +-- 2 files changed, 2 insertions(+), 3 deletions(-)