1 files changed, 34 insertions, 4 deletions

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 9fb9b312ab6b..0469aceaa230 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -2120,6 +2120,9 @@ static void setup_format_params(int track)
 	raw_cmd->kernel_data = floppy_track_buffer;
 	raw_cmd->length = 4 * F_SECT_PER_TRACK;
 
+	if (!F_SECT_PER_TRACK)
+		return;
+
 	/* allow for about 30ms for data transport per track */
 	head_shift = (F_SECT_PER_TRACK + 5) / 6;
 
@@ -3230,8 +3233,12 @@ static int set_geometry(unsigned int cmd, struct floppy_struct *g,
 	int cnt;
 
 	/* sanity checking for parameters. */
-	if (g->sect <= 0 ||
-	    g->head <= 0 ||
+	if ((int)g->sect <= 0 ||
+	    (int)g->head <= 0 ||
+	    /* check for overflow in max_sector */
+	    (int)(g->sect * g->head) <= 0 ||
+	    /* check for zero in F_SECT_PER_TRACK */
+	    (unsigned char)((g->sect << 2) >> FD_SIZECODE(g)) == 0 ||
 	    g->track <= 0 || g->track > UDP->tracks >> STRETCH(g) ||
 	    /* check if reserved bits are set */
 	    (g->stretch & ~(FD_STRETCH | FD_SWAPSIDES | FD_SECTBASEMASK)) != 0)
@@ -3375,6 +3382,24 @@ static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return 0;
 }
 
+static bool valid_floppy_drive_params(const short autodetect[8],
+		int native_format)
+{
+	size_t floppy_type_size = ARRAY_SIZE(floppy_type);
+	size_t i = 0;
+
+	for (i = 0; i < 8; ++i) {
+		if (autodetect[i] < 0 ||
+		    autodetect[i] >= floppy_type_size)
+			return false;
+	}
+
+	if (native_format < 0 || native_format >= floppy_type_size)
+		return false;
+
+	return true;
+}
+
 static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
 		    unsigned long param)
 {
@@ -3501,6 +3526,9 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int
 		SUPBOUND(size, strlen((const char *)outparam) + 1);
 		break;
 	case FDSETDRVPRM:
+		if (!valid_floppy_drive_params(inparam.dp.autodetect,
+				inparam.dp.native_format))
+			return -EINVAL;
 		*UDP = inparam.dp;
 		break;
 	case FDGETDRVPRM:
@@ -3698,6 +3726,8 @@ static int compat_setdrvprm(int drive,
 		return -EPERM;
 	if (copy_from_user(&v, arg, sizeof(struct compat_floppy_drive_params)))
 		return -EFAULT;
+	if (!valid_floppy_drive_params(v.autodetect, v.native_format))
+		return -EINVAL;
 	mutex_lock(&floppy_mutex);
 	UDP->cmos = v.cmos;
 	UDP->max_dtr = v.max_dtr;
@@ -3900,7 +3930,7 @@ static void __init config_types(void)
 	if (!UDP->cmos)
 		UDP->cmos = FLOPPY0_TYPE;
 	drive = 1;
-	if (!UDP->cmos && FLOPPY1_TYPE)
+	if (!UDP->cmos)
 		UDP->cmos = FLOPPY1_TYPE;
 
 	/* FIXME: additional physical CMOS drive detection should go here */
@@ -4424,7 +4454,7 @@ static int __init floppy_setup(char *str)
 		pr_cont("\n");
 	} else
 		DPRINT("botched floppy option\n");
-	DPRINT("Read Documentation/blockdev/floppy.txt\n");
+	DPRINT("Read Documentation/admin-guide/blockdev/floppy.rst\n");
 	return 0;
 }