| Message ID | 20240323084155.166835-1-shinichiro.kawasaki@wdc.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] scsi: mpi3mr: Avoid memcpy field-spanning write WARNING | expand |
On Sat, 23 Mar 2024 17:41:55 +0900, Shin'ichiro Kawasaki wrote: > When the "storcli2 show" command is executed for eHBA-9600, mpi3mr > driver prints this WARNING message: > > memcpy: detected field-spanning write (size 128) of single field "bsg_reply_buf->reply_buf" at drivers/scsi/mpi3mr/mpi3mr_app.c:1658 (size 1) > WARNING: CPU: 0 PID: 12760 at drivers/scsi/mpi3mr/mpi3mr_app.c:1658 mpi3mr_bsg_request+0x6b12/0x7f10 [mpi3mr] > > The cause of the WARN is 128 bytes memcpy to the 1 byte size array > "__u8 replay_buf[1]" in the struct mpi3mr_bsg_in_reply_buf. The array is > intended to be a flexible length array, then the WARN is a false > positive. To suppress the WARN, remove the constant number '1' from the > array declaration and clarify that it has flexible length. Also, adjust > the memory allocation size to match the change. > > [...] Applied to 6.9/scsi-fixes, thanks! [1/1] scsi: mpi3mr: Avoid memcpy field-spanning write WARNING https://git.kernel.org/mkp/scsi/c/429846b4b6ce
diff --git a/drivers/scsi/mpi3mr/mpi3mr_app.c b/drivers/scsi/mpi3mr/mpi3mr_app.c index 0380996b5ad2..55d590b91947 100644 --- a/drivers/scsi/mpi3mr/mpi3mr_app.c +++ b/drivers/scsi/mpi3mr/mpi3mr_app.c @@ -1644,7 +1644,7 @@ static long mpi3mr_bsg_process_mpt_cmds(struct bsg_job *job) if ((mpirep_offset != 0xFF) && drv_bufs[mpirep_offset].bsg_buf_len) { drv_buf_iter = &drv_bufs[mpirep_offset]; - drv_buf_iter->kern_buf_len = (sizeof(*bsg_reply_buf) - 1 + + drv_buf_iter->kern_buf_len = (sizeof(*bsg_reply_buf) + mrioc->reply_sz); bsg_reply_buf = kzalloc(drv_buf_iter->kern_buf_len, GFP_KERNEL); diff --git a/include/uapi/scsi/scsi_bsg_mpi3mr.h b/include/uapi/scsi/scsi_bsg_mpi3mr.h index c72ce387286a..30a5c1a59376 100644 --- a/include/uapi/scsi/scsi_bsg_mpi3mr.h +++ b/include/uapi/scsi/scsi_bsg_mpi3mr.h @@ -382,7 +382,7 @@ struct mpi3mr_bsg_in_reply_buf { __u8 mpi_reply_type; __u8 rsvd1; __u16 rsvd2; - __u8 reply_buf[1]; + __u8 reply_buf[]; }; /**
When the "storcli2 show" command is executed for eHBA-9600, mpi3mr driver prints this WARNING message: memcpy: detected field-spanning write (size 128) of single field "bsg_reply_buf->reply_buf" at drivers/scsi/mpi3mr/mpi3mr_app.c:1658 (size 1) WARNING: CPU: 0 PID: 12760 at drivers/scsi/mpi3mr/mpi3mr_app.c:1658 mpi3mr_bsg_request+0x6b12/0x7f10 [mpi3mr] The cause of the WARN is 128 bytes memcpy to the 1 byte size array "__u8 replay_buf[1]" in the struct mpi3mr_bsg_in_reply_buf. The array is intended to be a flexible length array, then the WARN is a false positive. To suppress the WARN, remove the constant number '1' from the array declaration and clarify that it has flexible length. Also, adjust the memory allocation size to match the change. Suggested-by: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> --- Changes from v1: * Modify the array declaration for flexible length instead of two memcpy calls drivers/scsi/mpi3mr/mpi3mr_app.c | 2 +- include/uapi/scsi/scsi_bsg_mpi3mr.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)