From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 22 Mar 2021 17:02:47 +0100
Subject: scsi: lpfc: Fix gcc -Wstringop-overread warning
Patch-mainline: v5.13-rc1
Git-commit: ada48ba70f6b98b7e93eea56770d6e6932734783
References: bsc#1185472
gcc-11 warns about an strnlen with a length larger than the size of the
passed buffer:
drivers/scsi/lpfc/lpfc_attr.c: In function 'lpfc_nvme_info_show':
drivers/scsi/lpfc/lpfc_attr.c:518:25: error: 'strnlen' specified bound 4095 exceeds source size 24 [-Werror=stringop-overread]
518 | strnlen(LPFC_NVME_INFO_MORE_STR, PAGE_SIZE - 1)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In this case, the code is entirely valid, as the string is properly
terminated, and the size argument is only there out of extra caution in
case it exceeds a page.
This cannot really happen here, so just simplify it to a sizeof().
Link: https://lore.kernel.org/r/20210322160253.4032422-10-arnd@kernel.org
Fixes: afff0d2321ea ("scsi: lpfc: Add Buffer overflow check, when nvme_info larger than PAGE_SIZE")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
drivers/scsi/lpfc/lpfc_attr.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -512,11 +512,9 @@ lpfc_nvme_info_show(struct device *dev,
"6314 Catching potential buffer "
"overflow > PAGE_SIZE = %lu bytes\n",
PAGE_SIZE);
- strlcpy(buf + PAGE_SIZE - 1 -
- strnlen(LPFC_NVME_INFO_MORE_STR, PAGE_SIZE - 1),
+ strlcpy(buf + PAGE_SIZE - 1 - sizeof(LPFC_NVME_INFO_MORE_STR),
LPFC_NVME_INFO_MORE_STR,
- strnlen(LPFC_NVME_INFO_MORE_STR, PAGE_SIZE - 1)
- + 1);
+ sizeof(LPFC_NVME_INFO_MORE_STR) + 1);
}
return len;