| Message ID | 20210401162054.GA397186@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [next] scsi: mpt3sas: Fix out-of-bounds warnings in _ctl_addnl_diag_query | expand |
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!
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
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]; };
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 <lkp@intel.com> Build-tested-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/60659889.bJJILx2THu3hlpxW%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/scsi/mpt3sas/mpt3sas_ctl.c | 5 ++--- drivers/scsi/mpt3sas/mpt3sas_ctl.h | 12 ++++-------- 2 files changed, 6 insertions(+), 11 deletions(-)