From: Arnd Bergmann arnd@arndb.de
[ Upstream commit ee4e7dfe4ffc9ca50c6875757bd119abfe22b5c5 ]
The ipr_log_vpd_compact() function triggers a fortified memcpy() warning about a potential string overflow with all versions of clang:
In file included from drivers/scsi/ipr.c:43: In file included from include/linux/string.h:254: include/linux/fortify-string.h:520:4: error: call to '__write_overflow_field' declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] __write_overflow_field(p_size_field, size); ^ include/linux/fortify-string.h:520:4: error: call to '__write_overflow_field' declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] 2 errors generated.
I don't see anything actually wrong with the function, but this is the only instance I can reproduce of the fortification going wrong in the kernel at the moment, so the easiest solution may be to rewrite the function into something that does not trigger the warning.
Instead of having a combined buffer for vendor/device/serial strings, use three separate local variables and just truncate the whitespace individually.
Link: https://lore.kernel.org/r/20230214132831.2118392-1-arnd@kernel.org Cc: Kees Cook keescook@chromium.org Fixes: 8cf093e275d0 ("[SCSI] ipr: Improved dual adapter errors") Signed-off-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Damien Le Moal damien.lemoal@opensource.wdc.com Reviewed-by: Kees Cook keescook@chromium.org Acked-by: Brian King brking@linux.vnet.ibm.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/ipr.c | 41 +++++++++++++++++++++-------------------- 1 file changed, 21 insertions(+), 20 deletions(-)
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c index 04fb7fc012264..e5e38431c5c73 100644 --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -1516,23 +1516,22 @@ static void ipr_process_ccn(struct ipr_cmnd *ipr_cmd) }
/** - * strip_and_pad_whitespace - Strip and pad trailing whitespace. - * @i: index into buffer - * @buf: string to modify + * strip_whitespace - Strip and pad trailing whitespace. + * @i: size of buffer + * @buf: string to modify * - * This function will strip all trailing whitespace, pad the end - * of the string with a single space, and NULL terminate the string. + * This function will strip all trailing whitespace and + * NUL terminate the string. * - * Return value: - * new length of string **/ -static int strip_and_pad_whitespace(int i, char *buf) +static void strip_whitespace(int i, char *buf) { + if (i < 1) + return; + i--; while (i && buf[i] == ' ') i--; - buf[i+1] = ' '; - buf[i+2] = '\0'; - return i + 2; + buf[i+1] = '\0'; }
/** @@ -1547,19 +1546,21 @@ static int strip_and_pad_whitespace(int i, char *buf) static void ipr_log_vpd_compact(char *prefix, struct ipr_hostrcb *hostrcb, struct ipr_vpd *vpd) { - char buffer[IPR_VENDOR_ID_LEN + IPR_PROD_ID_LEN + IPR_SERIAL_NUM_LEN + 3]; - int i = 0; + char vendor_id[IPR_VENDOR_ID_LEN + 1]; + char product_id[IPR_PROD_ID_LEN + 1]; + char sn[IPR_SERIAL_NUM_LEN + 1];
- memcpy(buffer, vpd->vpids.vendor_id, IPR_VENDOR_ID_LEN); - i = strip_and_pad_whitespace(IPR_VENDOR_ID_LEN - 1, buffer); + memcpy(vendor_id, vpd->vpids.vendor_id, IPR_VENDOR_ID_LEN); + strip_whitespace(IPR_VENDOR_ID_LEN, vendor_id);
- memcpy(&buffer[i], vpd->vpids.product_id, IPR_PROD_ID_LEN); - i = strip_and_pad_whitespace(i + IPR_PROD_ID_LEN - 1, buffer); + memcpy(product_id, vpd->vpids.product_id, IPR_PROD_ID_LEN); + strip_whitespace(IPR_PROD_ID_LEN, product_id);
- memcpy(&buffer[i], vpd->sn, IPR_SERIAL_NUM_LEN); - buffer[IPR_SERIAL_NUM_LEN + i] = '\0'; + memcpy(sn, vpd->sn, IPR_SERIAL_NUM_LEN); + strip_whitespace(IPR_SERIAL_NUM_LEN, sn);
- ipr_hcam_err(hostrcb, "%s VPID/SN: %s\n", prefix, buffer); + ipr_hcam_err(hostrcb, "%s VPID/SN: %s %s %s\n", prefix, + vendor_id, product_id, sn); }
/**