[PATCH 29/33] scsi: qla2xxx: Zero-init bsg stack buffers to avoid info leak

Several bsg handlers stage their request/reply in an uninitialized 256-byte
on-stack buffer (uint8_t bsg[DMA_POOL_SIZE]) and fill it via
sg_copy_to_buffer(), which only copies as many bytes as the user-supplied
request payload. When the request is shorter than the structure, the
remainder of the buffer is left holding stale stack data.

qla2x00_read_fru_status() and qla2x00_read_i2c() then copy the full
structure back to the reply payload with sg_copy_from_buffer(), leaking the
uninitialized stack bytes to user space. The write/update paths do not copy
the buffer back, but can feed uninitialized fields to the device.

Zero the stack buffer at declaration in all five handlers, mirroring the
heap kzalloc() approach, so short requests can no longer expose stale
memory.

Fixes: 697a4bc69159 ("[SCSI] qla2xxx: Provide method for updating I2C attached VPD.")
Fixes: 9ebb5d9c69f1 ("[SCSI] qla2xxx: Add I2C BSG interface.")
Cc: [email protected]
Reported-by: Sashiko <[email protected]>
Signed-off-by: Nilesh Javali <[email protected]>
---
 drivers/scsi/qla2xxx/qla_bsg.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_bsg.c b/drivers/scsi/qla2xxx/qla_bsg.c
index f9b693af8db1..49f66f37b1a7 100644
--- a/drivers/scsi/qla2xxx/qla_bsg.c
+++ b/drivers/scsi/qla2xxx/qla_bsg.c
@@ -1973,7 +1973,7 @@ qla2x00_update_fru_versions(struct bsg_job *bsg_job)
 	scsi_qla_host_t *vha = shost_priv(host);
 	struct qla_hw_data *ha = vha->hw;
 	int rval = 0;
-	uint8_t bsg[DMA_POOL_SIZE];
+	uint8_t bsg[DMA_POOL_SIZE] = {};
 	struct qla_image_version_list *list = (void *)bsg;
 	struct qla_image_version *image;
 	uint32_t count;
@@ -2033,7 +2033,7 @@ qla2x00_read_fru_status(struct bsg_job *bsg_job)
 	scsi_qla_host_t *vha = shost_priv(host);
 	struct qla_hw_data *ha = vha->hw;
 	int rval = 0;
-	uint8_t bsg[DMA_POOL_SIZE];
+	uint8_t bsg[DMA_POOL_SIZE] = {};
 	struct qla_status_reg *sr = (void *)bsg;
 	dma_addr_t sfp_dma;
 	uint8_t *sfp = dma_pool_alloc(ha->s_dma_pool, GFP_KERNEL, &sfp_dma);
@@ -2084,7 +2084,7 @@ qla2x00_write_fru_status(struct bsg_job *bsg_job)
 	scsi_qla_host_t *vha = shost_priv(host);
 	struct qla_hw_data *ha = vha->hw;
 	int rval = 0;
-	uint8_t bsg[DMA_POOL_SIZE];
+	uint8_t bsg[DMA_POOL_SIZE] = {};
 	struct qla_status_reg *sr = (void *)bsg;
 	dma_addr_t sfp_dma;
 	uint8_t *sfp = dma_pool_alloc(ha->s_dma_pool, GFP_KERNEL, &sfp_dma);
@@ -2131,7 +2131,7 @@ qla2x00_write_i2c(struct bsg_job *bsg_job)
 	scsi_qla_host_t *vha = shost_priv(host);
 	struct qla_hw_data *ha = vha->hw;
 	int rval = 0;
-	uint8_t bsg[DMA_POOL_SIZE];
+	uint8_t bsg[DMA_POOL_SIZE] = {};
 	struct qla_i2c_access *i2c = (void *)bsg;
 	dma_addr_t sfp_dma;
 	uint8_t *sfp = dma_pool_alloc(ha->s_dma_pool, GFP_KERNEL, &sfp_dma);
@@ -2177,7 +2177,7 @@ qla2x00_read_i2c(struct bsg_job *bsg_job)
 	scsi_qla_host_t *vha = shost_priv(host);
 	struct qla_hw_data *ha = vha->hw;
 	int rval = 0;
-	uint8_t bsg[DMA_POOL_SIZE];
+	uint8_t bsg[DMA_POOL_SIZE] = {};
 	struct qla_i2c_access *i2c = (void *)bsg;
 	dma_addr_t sfp_dma;
 	uint8_t *sfp = dma_pool_alloc(ha->s_dma_pool, GFP_KERNEL, &sfp_dma);
-- 
2.47.3