[U-Boot] [PATCH] mtdparts: fixed buffer overflow bug

[U-Boot] [PATCH] mtdparts: fixed buffer overflow bug

[Kay Potthoff]

In the case that there was no name defined for a partition the
code assumes that name_len is 22 and therefore allocates exactly
that space for a dummy name. But the function sprintf() first
resolves "0x%08llx at 0x%08llx" to a string that is longer than 22
bytes. This leads to a buffer overflow. The replacement function
snprintf() limits the copied bytes to name_len and therefore
avoids the buffer overflow.

Signed-off-by: Kay Potthoff <Kay.Potthoff@microsys.de>
---
 cmd/mtdparts.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cmd/mtdparts.c b/cmd/mtdparts.c
index 9bc977450cf8..d0cda1bea400 100644
--- a/cmd/mtdparts.c
+++ b/cmd/mtdparts.c
@@ -691,7 +691,7 @@ static int part_parse(const char *const partdef, const char **ret, struct part_i
 		part->auto_name = 0;
 	} else {
 		/* auto generated name in form of size at offset */
-		sprintf(part->name, "0x%08llx at 0x%08llx", size, offset);
+		snprintf(part->name, name_len, "0x%08llx at 0x%08llx", size, offset);
 		part->auto_name = 1;
 	}
 
-- 
2.17.0

[U-Boot] mtdparts: fixed buffer overflow bug

[Tom Rini]

On Tue, Jul 17, 2018 at 08:19:39AM +0200, Kay Potthoff wrote:

> In the case that there was no name defined for a partition the
> code assumes that name_len is 22 and therefore allocates exactly
> that space for a dummy name. But the function sprintf() first
> resolves "0x%08llx at 0x%08llx" to a string that is longer than 22
> bytes. This leads to a buffer overflow. The replacement function
> snprintf() limits the copied bytes to name_len and therefore
> avoids the buffer overflow.
> 
> Signed-off-by: Kay Potthoff <Kay.Potthoff@microsys.de>

Applied to u-boot/master, thanks!

-- 
Tom
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