From 1b61680cfe3e4dce1e4dcf41d47d92b85c3fcceb Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 8 Apr 2024 21:48:09 +0200 Subject: staging: rts5208: replace weird strncpy() with memcpy() When -Wstringop-truncation is enabled, gcc finds a function that always does a short copy: In function 'inquiry', inlined from 'rtsx_scsi_handler' at drivers/staging/rts5208/rtsx_scsi.c:3210:12: drivers/staging/rts5208/rtsx_scsi.c:526:17: error: 'strncpy' output truncated copying between 1 and 28 bytes from a string of length 28 [-Werror=stringop-truncation] 526 | strncpy(buf + 8, inquiry_string, sendbytes - 8); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The code originally had a memcpy() that would overread the source string, and commit 88a5b39b69ab ("staging/rts5208: Fix read overflow in memcpy") fixed this but introduced the warning about truncation in the process. As Dan points out, the final space in the inquiry_string always gets cut off, so remove it here for clarity, leaving exactly the 28 non-NUL characters that can get copied into the output. In the 'pro_formatter_flag' this is followed by another 20 bytes from the 'formatter_inquiry_str' array, but there the output never contains a NUL-termination, and the length is known, so memcpy() is the more logical choice. Cc: Dan Carpenter Link: https://lore.kernel.org/lkml/695be581-548f-4e5e-a211-5f3b95568e77@moroto.mountain/ Signed-off-by: Arnd Bergmann Reviewed-by: Dan Carpenter Reviewed-by: Justin Stitt Link: https://lore.kernel.org/r/20240408194821.3183462-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rts5208/rtsx_scsi.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/staging/rts5208/rtsx_scsi.c b/drivers/staging/rts5208/rtsx_scsi.c index 08bd768ad34d..c27cffb9ad8f 100644 --- a/drivers/staging/rts5208/rtsx_scsi.c +++ b/drivers/staging/rts5208/rtsx_scsi.c @@ -463,10 +463,10 @@ static unsigned char formatter_inquiry_str[20] = { static int inquiry(struct scsi_cmnd *srb, struct rtsx_chip *chip) { unsigned int lun = SCSI_LUN(srb); - char *inquiry_default = (char *)"Generic-xD/SD/M.S. 1.00 "; - char *inquiry_sdms = (char *)"Generic-SD/MemoryStick 1.00 "; - char *inquiry_sd = (char *)"Generic-SD/MMC 1.00 "; - char *inquiry_ms = (char *)"Generic-MemoryStick 1.00 "; + char *inquiry_default = (char *)"Generic-xD/SD/M.S. 1.00"; + char *inquiry_sdms = (char *)"Generic-SD/MemoryStick 1.00"; + char *inquiry_sd = (char *)"Generic-SD/MMC 1.00"; + char *inquiry_ms = (char *)"Generic-MemoryStick 1.00"; char *inquiry_string; unsigned char sendbytes; unsigned char *buf; @@ -523,7 +523,7 @@ static int inquiry(struct scsi_cmnd *srb, struct rtsx_chip *chip) if (sendbytes > 8) { memcpy(buf, inquiry_buf, 8); - strncpy(buf + 8, inquiry_string, sendbytes - 8); + memcpy(buf + 8, inquiry_string, min(sendbytes, 36) - 8); if (pro_formatter_flag) { /* Additional Length */ buf[4] = 0x33; -- cgit v1.2.3