[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL v2 3/7] linux-user: avoid string truncation warnings
From: |
Laurent Vivier |
Subject: |
[Qemu-devel] [PULL v2 3/7] linux-user: avoid string truncation warnings in uname field copying |
Date: |
Fri, 10 May 2019 12:45:32 +0200 |
From: Daniel P. Berrangé <address@hidden>
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 <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Laurent Vivier <address@hidden>
---
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 313b79dbad47..1c05f95387f4 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)
--
2.20.1
- [Qemu-devel] [PULL v2 0/7] Linux user for 4.1 patches, Laurent Vivier, 2019/05/10
- [Qemu-devel] [PULL v2 1/7] linux-user: Add missing IPV6 sockopts, Laurent Vivier, 2019/05/10
- [Qemu-devel] [PULL v2 6/7] linux-user: avoid treading on gprof's SIGPROF signals, Laurent Vivier, 2019/05/10
- [Qemu-devel] [PULL v2 7/7] linux-user: fix GPROF build failure, Laurent Vivier, 2019/05/10
- [Qemu-devel] [PULL v2 2/7] linux-user/elfload: Fix GCC 9 build warnings, Laurent Vivier, 2019/05/10
- [Qemu-devel] [PULL v2 5/7] linux-user: elf: Map empty PT_LOAD segments, Laurent Vivier, 2019/05/10
- [Qemu-devel] [PULL v2 3/7] linux-user: avoid string truncation warnings in uname field copying,
Laurent Vivier <=
- [Qemu-devel] [PULL v2 4/7] The ioctl(SIOCGIFNAME) call requires a struct ifreq., Laurent Vivier, 2019/05/10
- Re: [Qemu-devel] [PULL v2 0/7] Linux user for 4.1 patches, Peter Maydell, 2019/05/10