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password: Fix warning with empty default password

PATCH Applied David Dgien 2 participants 2 messages May 23, 2020 – May 25, 2020

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David Dgien

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#0 lore raw

PATCH v2 1/1 password: Fix warning with empty default password

When CONFIG_PASSWORD_DEFAULT is unset, the default_passwd buffer is set to the empty string. The read_default_passwd() function wants to read at least two characters from that buffer, causing GCC to generate an array bounds warning:

barebox/common/password.c: In function 'login':
barebox/common/password.c:173:5: warning: array subscript [1, 2147483647] is outside array bounds of 'const char[1]' [-Warray-bounds] In file included from barebox/common/password.c:30:
include/generated/passwd.h:1:19: note: while referencing 'default_passwd'

Add an ARRAY_SIZE check to default_passwd so that the loop is optimized away and the warning is no longer generated. Since the read_default_passwd() function is only called when default_passwd is not the empty string, this is not a functional change.

Signed-off-by David Dgien <[email protected]>

---
Changes since v1:
- Added warning output to commit message
- Rework fix in read_default_passwd() instead of hacking with the makefile

 common/password.c | 3 +++
 1 file changed, 3 insertions(+)
common/password.c +3 -0
index a2a9c4cd6..3a0547b9a 100644
@@ -161,6 +161,9 @@ static int read_default_passwd(unsigned char *sum, size_t length)
 	unsigned char *buf = (unsigned char *)default_passwd;
 	unsigned char c;
 
+	if (ARRAY_SIZE(default_passwd) == 1)
+		return -ENOSYS;
+
 	if (!sum || length < 1)
 		return -EINVAL;
Signature · 7 lines
2.26.2


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Applied
#1 lore raw
Quoted 15 lines · David Dgien

When CONFIG_PASSWORD_DEFAULT is unset, the default_passwd buffer is set to the empty string. The read_default_passwd() function wants to read at least two characters from that buffer, causing GCC to generate an array bounds warning:

barebox/common/password.c: In function 'login':
barebox/common/password.c:173:5: warning: array subscript [1, 2147483647] is outside array bounds of 'const char[1]' [-Warray-bounds] In file included from barebox/common/password.c:30:
include/generated/passwd.h:1:19: note: while referencing 'default_passwd'

Add an ARRAY_SIZE check to default_passwd so that the loop is optimized away and the warning is no longer generated. Since the read_default_passwd() function is only called when default_passwd is not the empty string, this is not a functional change.

Quoted 8 lines
Signed-off-by David Dgien <[email protected]>

---
Changes since v1:
- Added warning output to commit message
- Rework fix in read_default_passwd() instead of hacking with the makefile

 common/password.c | 3 +++
 1 file changed, 3 insertions(+)

Applied, thanks

Sascha

Signature · 9 lines
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