From: "Gustavo A. R. Silva" <[email protected]>
purex_item.iocb is defined as a 64-element u8 array, but 64 is the
minimum size and it can be allocated larger. This makes it a standard
empty flex array.
This was motivated by field-spanning write warnings during FPIN testing.
> kernel: memcpy: detected field-spanning write (size 60) of single
> field "((uint8_t *)fpin_pkt + buffer_copy_offset)"
> at drivers/scsi/qla2xxx/qla_isr.c:1221 (size 44)
I removed the outer wrapper from the iocb flex array, so that it can be
linked to `purex_item.size` with `__counted_by`.
These changes remove the default minimum 64-byte allocation, requiring
further changes.
In `struct scsi_qla_host` the embedded `default_item` is now followed
by `__default_item_iocb[QLA_DEFAULT_PAYLOAD_SIZE]` to reserve space
that will be used as `default_item.iocb`. This is wrapped using the
`TRAILING_OVERLAP()` macro helper, which effectively creates a union
between flexible-array member `default_item.iocb` and
`__default_item_iocb`.
Since `struct pure_item` now contains a flexible-array member, the
helper must be placed at the end of `struct scsi_qla_host` to prevent
a `-Wflex-array-member-not-at-end` warning.
`qla24xx_alloc_purex_item()` is adjusted to no longer expect the
default minimum size to be part of `sizeof(struct purex_item)`,
the entire flexible array size is added to the structure size for
allocation.
This also slightly changes the layout of the purex_item struct, as
2-bytes of padding are added between `size` and `iocb`. The resulting
size is the same, but iocb is shifted 2-bytes (the original `purex_item`
structure was padded at the end, after the 64-byte defined array size).
I don't think this is a problem.
In qla_os.c:qla24xx_process_purex_rdp()
To avoid a null pointer dereference the vha->default_item should be set
to 0 last if the item pointer passed to the function matches. Also use
a local variable to avoid multiple de-referencing of the item.
Tested-by: Bryan Gurney <[email protected]>
Co-developed-by: Chris Leech <[email protected]>
Signed-off-by: Chris Leech <[email protected]>
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/scsi/qla2xxx/qla_def.h | 10 ++++++----
drivers/scsi/qla2xxx/qla_isr.c | 17 ++++++++---------
drivers/scsi/qla2xxx/qla_nvme.c | 2 +-
drivers/scsi/qla2xxx/qla_os.c | 9 ++++++---
4 files changed, 21 insertions(+), 17 deletions(-)
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index cb95b7b12051..604e66bead1e 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -4890,9 +4890,7 @@ struct purex_item {
struct purex_item *pkt);
atomic_t in_use;
uint16_t size;
- struct {
- uint8_t iocb[64];
- } iocb;
+ uint8_t iocb[] __counted_by(size);
};
#include "qla_edif.h"
@@ -5101,7 +5099,6 @@ typedef struct scsi_qla_host {
struct list_head head;
spinlock_t lock;
} purex_list;
- struct purex_item default_item;
struct name_list_extended gnl;
/* Count of active session/fcport */
@@ -5130,6 +5127,11 @@ typedef struct scsi_qla_host {
#define DPORT_DIAG_IN_PROGRESS BIT_0
#define DPORT_DIAG_CHIP_RESET_IN_PROGRESS BIT_1
uint16_t dport_status;
+
+ /* Must be last --ends in a flexible-array member. */
+ TRAILING_OVERLAP(struct purex_item, default_item, iocb,
+ uint8_t __default_item_iocb[QLA_DEFAULT_PAYLOAD_SIZE];
+ );
} scsi_qla_host_t;
struct qla27xx_image_status {
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 8ff8781dae47..ccb044693dcb 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -1078,17 +1078,17 @@ static struct purex_item *
qla24xx_alloc_purex_item(scsi_qla_host_t *vha, uint16_t size)
{
struct purex_item *item = NULL;
- uint8_t item_hdr_size = sizeof(*item);
if (size > QLA_DEFAULT_PAYLOAD_SIZE) {
- item = kzalloc(item_hdr_size +
- (size - QLA_DEFAULT_PAYLOAD_SIZE), GFP_ATOMIC);
+ item = kzalloc(struct_size(item, iocb, size), GFP_ATOMIC);
} else {
if (atomic_inc_return(&vha->default_item.in_use) == 1) {
item = &vha->default_item;
goto initialize_purex_header;
} else {
- item = kzalloc(item_hdr_size, GFP_ATOMIC);
+ item = kzalloc(
+ struct_size(item, iocb, QLA_DEFAULT_PAYLOAD_SIZE),
+ GFP_ATOMIC);
}
}
if (!item) {
@@ -1128,17 +1128,16 @@ qla24xx_queue_purex_item(scsi_qla_host_t *vha, struct
purex_item *pkt,
* @vha: SCSI driver HA context
* @pkt: ELS packet
*/
-static struct purex_item
-*qla24xx_copy_std_pkt(struct scsi_qla_host *vha, void *pkt)
+static struct purex_item *
+qla24xx_copy_std_pkt(struct scsi_qla_host *vha, void *pkt)
{
struct purex_item *item;
- item = qla24xx_alloc_purex_item(vha,
- QLA_DEFAULT_PAYLOAD_SIZE);
+ item = qla24xx_alloc_purex_item(vha, QLA_DEFAULT_PAYLOAD_SIZE);
if (!item)
return item;
- memcpy(&item->iocb, pkt, sizeof(item->iocb));
+ memcpy(&item->iocb, pkt, QLA_DEFAULT_PAYLOAD_SIZE);
return item;
}
diff --git a/drivers/scsi/qla2xxx/qla_nvme.c b/drivers/scsi/qla2xxx/qla_nvme.c
index 8ee2e337c9e1..92488890bc04 100644
--- a/drivers/scsi/qla2xxx/qla_nvme.c
+++ b/drivers/scsi/qla2xxx/qla_nvme.c
@@ -1308,7 +1308,7 @@ void qla2xxx_process_purls_iocb(void **pkt, struct
rsp_que **rsp)
ql_dbg(ql_dbg_unsol, vha, 0x2121,
"PURLS OP[%01x] size %d xchg addr 0x%x portid %06x\n",
- item->iocb.iocb[3], item->size, uctx->exchange_address,
+ item->iocb[3], item->size, uctx->exchange_address,
fcport->d_id.b24);
/* +48 0 1 2 3 4 5 6 7 8 9 A B C D E F
* ----- -----------------------------------------------
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index d4b484c0fd9d..32437bae1a30 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -6459,9 +6459,12 @@ void qla24xx_process_purex_rdp(struct scsi_qla_host *vha,
void
qla24xx_free_purex_item(struct purex_item *item)
{
- if (item == &item->vha->default_item)
- memset(&item->vha->default_item, 0, sizeof(struct purex_item));
- else
+ scsi_qla_host_t *base_vha = item->vha;
+
+ if (item == &base_vha->default_item) {
+ memset(&base_vha->__default_item_iocb, 0, QLA_DEFAULT_PAYLOAD_SIZE);
+ memset(&base_vha->default_item, 0, sizeof(struct purex_item));
+ } else
kfree(item);
}
