Patch "firmware: cs_dsp: Return error if block header overflows file" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    firmware: cs_dsp: Return error if block header overflows file

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     firmware-cs_dsp-return-error-if-block-header-overflo.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 777cdb6e68ad8c793e71749cab2fb4ee3f97e353
Author: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
Date:   Thu Jun 27 15:14:30 2024 +0100

    firmware: cs_dsp: Return error if block header overflows file
    
    [ Upstream commit 959fe01e85b7241e3ec305d657febbe82da16a02 ]
    
    Return an error from cs_dsp_power_up() if a block header is longer
    than the amount of data left in the file.
    
    The previous code in cs_dsp_load() and cs_dsp_load_coeff() would loop
    while there was enough data left in the file for a valid region. This
    protected against overrunning the end of the file data, but it didn't
    abort the file processing with an error.
    
    Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
    Fixes: f6bc909e7673 ("firmware: cs_dsp: add driver to support firmware loading on Cirrus Logic DSPs")
    Link: https://patch.msgid.link/20240627141432.93056-3-rf@xxxxxxxxxxxxxxxxxxxxx
    Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c
index f0c3c4011411d..28d24cf4456da 100644
--- a/drivers/firmware/cirrus/cs_dsp.c
+++ b/drivers/firmware/cirrus/cs_dsp.c
@@ -1390,8 +1390,13 @@ static int cs_dsp_load(struct cs_dsp *dsp, const struct firmware *firmware,
 	cs_dsp_dbg(dsp, "%s: timestamp %llu\n", file,
 		   le64_to_cpu(footer->timestamp));
 
-	while (pos < firmware->size &&
-	       sizeof(*region) < firmware->size - pos) {
+	while (pos < firmware->size) {
+		/* Is there enough data for a complete block header? */
+		if (sizeof(*region) > firmware->size - pos) {
+			ret = -EOVERFLOW;
+			goto out_fw;
+		}
+
 		region = (void *)&(firmware->data[pos]);
 		region_name = "Unknown";
 		reg = 0;
@@ -2079,8 +2084,13 @@ static int cs_dsp_load_coeff(struct cs_dsp *dsp, const struct firmware *firmware
 	pos = le32_to_cpu(hdr->len);
 
 	blocks = 0;
-	while (pos < firmware->size &&
-	       sizeof(*blk) < firmware->size - pos) {
+	while (pos < firmware->size) {
+		/* Is there enough data for a complete block header? */
+		if (sizeof(*blk) > firmware->size - pos) {
+			ret = -EOVERFLOW;
+			goto out_fw;
+		}
+
 		blk = (void *)(&firmware->data[pos]);
 
 		type = le16_to_cpu(blk->type);