usb: gadget/function/f_fs string table fix for multiple languages

PATCH New Dean Anderson 1 participant 1 message Mar 17, 2021

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Media (V4L/DVB) USB

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Dean Anderson

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2021-03-17 23:03 UTC #0 lore raw

PATCH 1/1 usb: gadget/function/f_fs string table fix for multiple languages

Fixes bug with the handling of more than one language in the string table in f_fs.c.
str_count was not reset for subsequent language codes. str_count-- "rolls under" and processes u32 max strings on the processing of the second language entry.
The existing bug can be reproduced by adding a second language table to the structure "strings" in tools/usb/ffs-test.c.

Signed-off-by Dean Anderson <[email protected]>

---
 drivers/usb/gadget/function/f_fs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

drivers/usb/gadget/function/f_fs.c +2 -1

index 801a8b668..10a5d9f0f 100644
@@ -2640,6 +2640,7 @@ static int __ffs_data_got_strings(struct ffs_data *ffs,
 
 	do { /* lang_count > 0 so we can use do-while */
 		unsigned needed = needed_count;
+		u32 str_per_lang = str_count;
 
 		if (len < 3)
 			goto error_free;

@@ -2675,7 +2676,7 @@ static int __ffs_data_got_strings(struct ffs_data *ffs,
 
 			data += length + 1;
 			len -= length + 1;
-		} while (--str_count);
+		} while (--str_per_lang);
 
 		s->id = 0;   /* terminator */
 		s->s = NULL;

Signature · 1 line

2.17.1