[PATCH 4.15 24/55] scsi: aacraid: Fix udev inquiry race condition

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@xxxxxxxxxxxxx>

commit f4e8708d3104437fd7716e957f38c265b0c509ef upstream.

When udev requests for a devices inquiry string, it might create multiple
threads causing a race condition on the shared inquiry resource string.

Created a buffer with the string for each thread.

Fixes: 3bc8070fb75b3315 ([SCSI] aacraid: SMC vendor identification)
Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@xxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/scsi/aacraid/aachba.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -913,8 +913,16 @@ static void setinqstr(struct aac_dev *de
 	memset(str, ' ', sizeof(*str));
 
 	if (sup_adap_info->adapter_type_text[0]) {
-		char *cp = sup_adap_info->adapter_type_text;
 		int c;
+		char *cp;
+		char *cname = kmemdup(sup_adap_info->adapter_type_text,
+				sizeof(sup_adap_info->adapter_type_text),
+								GFP_ATOMIC);
+
+		if (!cname)
+			return;
+
+		cp = cname;
 		if ((cp[0] == 'A') && (cp[1] == 'O') && (cp[2] == 'C'))
 			inqstrcpy("SMC", str->vid);
 		else {
@@ -923,7 +931,7 @@ static void setinqstr(struct aac_dev *de
 				++cp;
 			c = *cp;
 			*cp = '\0';
-			inqstrcpy(sup_adap_info->adapter_type_text, str->vid);
+			inqstrcpy(cname, str->vid);
 			*cp = c;
 			while (*cp && *cp != ' ')
 				++cp;
@@ -937,8 +945,8 @@ static void setinqstr(struct aac_dev *de
 			cp[sizeof(str->pid)] = '\0';
 		}
 		inqstrcpy (cp, str->pid);
-		if (c)
-			cp[sizeof(str->pid)] = c;
+
+		kfree(cname);
 	} else {
 		struct aac_driver_ident *mp = aac_get_driver_ident(dev->cardtype);