Fix the following out-of-bounds warnings by embedding existing
struct htb_rel_query into struct mpt3_addnl_diag_query, instead
of duplicating its members:
include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset [19, 32] from the object at 'karg' is out of the bounds of referenced subobject 'buffer_rel_condition' with type 'short unsigned int' at offset 16 [-Warray-bounds]
include/linux/fortify-string.h:22:29: warning: '__builtin_memset' offset [19, 32] from the object at 'karg' is out of the bounds of referenced subobject 'buffer_rel_condition' with type 'short unsigned int' at offset 16 [-Warray-bounds]
The problem is that the original code is trying to copy data into a
bunch of struct members adjacent to each other in a single call to
memcpy(). All those members are exactly the same contained in struct
htb_rel_query, so instead of duplicating them into struct
mpt3_addnl_diag_query, replace them with new member rel_query of
type struct htb_rel_query. So, now that this new object is introduced,
memcpy() doesn't overrun the length of &karg.buffer_rel_condition,
because the address of the new struct object _rel_query_ is used as
destination, instead. The same issue is present when calling memset(),
and it is fixed with this same approach.
Below is a comparison of struct mpt3_addnl_diag_query, before and after
this change (the size and cachelines remain the same):
$ pahole -C mpt3_addnl_diag_query drivers/scsi/mpt3sas/mpt3sas_ctl.o
struct mpt3_addnl_diag_query {
struct mpt3_ioctl_header hdr; /* 0 12 */
uint32_t unique_id; /* 12 4 */
uint16_t buffer_rel_condition; /* 16 2 */
uint16_t reserved1; /* 18 2 */
uint32_t trigger_type; /* 20 4 */
uint32_t trigger_info_dwords[2]; /* 24 8 */
uint32_t reserved2[2]; /* 32 8 */
/* size: 40, cachelines: 1, members: 7 */
/* last cacheline: 40 bytes */
};
$ pahole -C mpt3_addnl_diag_query drivers/scsi/mpt3sas/mpt3sas_ctl.o
struct mpt3_addnl_diag_query {
struct mpt3_ioctl_header hdr; /* 0 12 */
uint32_t unique_id; /* 12 4 */
struct htb_rel_query rel_query; /* 16 16 */
uint32_t reserved2[2]; /* 32 8 */
/* size: 40, cachelines: 1, members: 4 */
/* last cacheline: 40 bytes */
};
Also, 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().
Link: https://github.com/KSPP/linux/issues/109
Reported-by: kernel test robot <[email protected]>
Build-tested-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/lkml/60659889.bJJILx2THu3hlpxW%[email protected]/
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/scsi/mpt3sas/mpt3sas_ctl.c | 5 ++---
drivers/scsi/mpt3sas/mpt3sas_ctl.h | 12 ++++--------
2 files changed, 6 insertions(+), 11 deletions(-)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
index e7582fb8a93f..b66140e4c370 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
@@ -2507,7 +2507,7 @@ _ctl_addnl_diag_query(struct MPT3SAS_ADAPTER *ioc, void __user *arg)
__func__, karg.unique_id);
return -EPERM;
}
- memset(&karg.buffer_rel_condition, 0, sizeof(struct htb_rel_query));
+ memset(&karg.rel_query, 0, sizeof(karg.rel_query));
if ((ioc->diag_buffer_status[buffer_type] &
MPT3_DIAG_BUFFER_IS_REGISTERED) == 0) {
ioc_info(ioc, "%s: buffer_type(0x%02x) is not registered\n",
@@ -2520,8 +2520,7 @@ _ctl_addnl_diag_query(struct MPT3SAS_ADAPTER *ioc, void __user *arg)
__func__, buffer_type);
return -EPERM;
}
- memcpy(&karg.buffer_rel_condition, &ioc->htb_rel,
- sizeof(struct htb_rel_query));
+ memcpy(&karg.rel_query, &ioc->htb_rel, sizeof(karg.rel_query));
out:
if (copy_to_user(arg, &karg, sizeof(struct mpt3_addnl_diag_query))) {
ioc_err(ioc, "%s: unable to write mpt3_addnl_diag_query data @ %p\n",
diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.h b/drivers/scsi/mpt3sas/mpt3sas_ctl.h
index d2ccdafb8df2..8f6ffb40261c 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.h
@@ -50,6 +50,8 @@
#include <linux/miscdevice.h>
#endif
+#include "mpt3sas_base.h"
+
#ifndef MPT2SAS_MINOR
#define MPT2SAS_MINOR (MPT_MINOR + 1)
#endif
@@ -436,19 +438,13 @@ struct mpt3_diag_read_buffer {
* struct mpt3_addnl_diag_query - diagnostic buffer release reason
* @hdr - generic header
* @unique_id - unique id associated with this buffer.
- * @buffer_rel_condition - Release condition ioctl/sysfs/reset
- * @reserved1
- * @trigger_type - Master/Event/scsi/MPI
- * @trigger_info_dwords - Data Correspondig to trigger type
+ * @rel_query - release query.
* @reserved2
*/
struct mpt3_addnl_diag_query {
struct mpt3_ioctl_header hdr;
uint32_t unique_id;
- uint16_t buffer_rel_condition;
- uint16_t reserved1;
- uint32_t trigger_type;
- uint32_t trigger_info_dwords[2];
+ struct htb_rel_query rel_query;
uint32_t reserved2[2];
};
--
2.27.0
Gustavo,
> Fix the following out-of-bounds warnings by embedding existing struct
> htb_rel_query into struct mpt3_addnl_diag_query, instead of
> duplicating its members:
Applied to 5.13/scsi-staging, thanks!
--
Martin K. Petersen Oracle Linux Engineering
On Thu, 1 Apr 2021 11:20:54 -0500, Gustavo A. R. Silva wrote:
> Fix the following out-of-bounds warnings by embedding existing
> struct htb_rel_query into struct mpt3_addnl_diag_query, instead
> of duplicating its members:
>
> include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset [19, 32] from the object at 'karg' is out of the bounds of referenced subobject 'buffer_rel_condition' with type 'short unsigned int' at offset 16 [-Warray-bounds]
> include/linux/fortify-string.h:22:29: warning: '__builtin_memset' offset [19, 32] from the object at 'karg' is out of the bounds of referenced subobject 'buffer_rel_condition' with type 'short unsigned int' at offset 16 [-Warray-bounds]
>
> [...]
Applied to 5.13/scsi-queue, thanks!
[1/1] scsi: mpt3sas: Fix out-of-bounds warnings in _ctl_addnl_diag_query
https://git.kernel.org/mkp/scsi/c/16660db3fc2a
--
Martin K. Petersen Oracle Linux Engineering