| Message ID | 543BE352.3080609@gmail.com |
|---|---|
| State | New |
| Headers | show |
On 13.10.14 16:36, Chen Gang wrote: > strncat() will append additional '\0' to destination buffer, so need > additional 1 byte for it, or may cause memory overflow, just like other > area within QEMU have done. > > Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> I agree with this patch. However, the code is pretty ugly - I'm sure it must've been me who wrote it :). Could you please instead rewrite it to use g_strdup_printf() rather than strncat()s? That way we resolve all string pitfalls automatically - and this code is not the fast path, so doing an extra memory allocation is ok. Alex > --- > target-ppc/kvm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c > index 9c23c6b..66e7ce5 100644 > --- a/target-ppc/kvm.c > +++ b/target-ppc/kvm.c > @@ -1794,8 +1794,8 @@ static uint64_t kvmppc_read_int_cpu_dt(const char *propname) > return -1; > } > > - strncat(buf, "/", sizeof(buf) - strlen(buf)); > - strncat(buf, propname, sizeof(buf) - strlen(buf)); > + strncat(buf, "/", sizeof(buf) - strlen(buf) - 1); > + strncat(buf, propname, sizeof(buf) - strlen(buf) - 1); > > f = fopen(buf, "rb"); > if (!f) { >
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index 9c23c6b..66e7ce5 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -1794,8 +1794,8 @@ static uint64_t kvmppc_read_int_cpu_dt(const char *propname) return -1; } - strncat(buf, "/", sizeof(buf) - strlen(buf)); - strncat(buf, propname, sizeof(buf) - strlen(buf)); + strncat(buf, "/", sizeof(buf) - strlen(buf) - 1); + strncat(buf, propname, sizeof(buf) - strlen(buf) - 1); f = fopen(buf, "rb"); if (!f) {
strncat() will append additional '\0' to destination buffer, so need additional 1 byte for it, or may cause memory overflow, just like other area within QEMU have done. Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> --- target-ppc/kvm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)