qemu/0039-linux-user-avoid-string-truncation-.patch
2019-05-14 22:20:21 +00:00

48 lines
2.0 KiB
Diff
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Wed, 1 May 2019 15:46:46 +0100
Subject: linux-user: avoid string truncation warnings in uname field copying
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
In file included from /usr/include/string.h:494,
from include/qemu/osdep.h:101,
from linux-user/uname.c:20:
In function strncpy,
inlined from sys_uname at linux-user/uname.c:94:3:
/usr/include/bits/string_fortified.h:106:10: warning: __builtin_strncpy output may be truncated copying 64 bytes from a string of length 64 [-Wstringop-truncation]
106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We don't care where the NUL terminator in the original uname
field was. It suffices to copy the entire original field and
simply force a NUL terminator at the end of the new field.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190501144646.4851-1-berrange@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
[BR: Played with indent to avoid error from checkpatch.pl]
(cherry picked from commit b2acfb55962bc8caeaa50a5158da2f701f2c1f7c)
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
linux-user/uname.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/linux-user/uname.c b/linux-user/uname.c
index 313b79dbad..0c6ddf2ad9 100644
--- a/linux-user/uname.c
+++ b/linux-user/uname.c
@@ -72,9 +72,8 @@ const char *cpu_to_uname_machine(void *cpu_env)
#define COPY_UTSNAME_FIELD(dest, src) \
do { \
- /* __NEW_UTS_LEN doesn't include terminating null */ \
- (void) strncpy((dest), (src), __NEW_UTS_LEN); \
- (dest)[__NEW_UTS_LEN] = '\0'; \
+ memcpy((dest), (src), MIN(sizeof(src), sizeof(dest))); \
+ (dest)[sizeof(dest) - 1] = '\0'; \
} while (0)
int sys_uname(struct new_utsname *buf)