On 7/12/22 00:46, David Gibson wrote:
On Mon, Jul 11, 2022 at 04:37:43PM -0300, Murilo Opsfelder Araujo wrote:Some systems have /proc/device-tree/cpus/../clock-frequency. However, this is not the expected path for a CPU device tree directory. Signed-off-by: Murilo Opsfelder Araujo <muri...@linux.ibm.com> Signed-off-by: Fabiano Rosas <faro...@linux.ibm.com> --- target/ppc/kvm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index 6eed466f80..c8485a5cc0 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -1877,6 +1877,12 @@ static int kvmppc_find_cpu_dt(char *buf, int buf_len) buf[0] = '\0'; while ((dirp = readdir(dp)) != NULL) { FILE *f; + + /* Don't accidentally read from the upper directory */ + if (strcmp(dirp->d_name, "..") == 0) {It might not be causing problems now, but it would be technically more correct to also skip ".", wouldn't it?
Given that the use of this function is inside kvmppc_read_int_cpu_dt(), which is used to read a property that belongs to a CPU node, I believe you're right. It's better to avoid returning "PROC_DEVTREE_CPU" as well. Murilo, can you please re-send it skipping both ".." and "." ? Better be on the safe side. Daniel
+ continue; + } + snprintf(buf, buf_len, "%s%s/clock-frequency", PROC_DEVTREE_CPU, dirp->d_name); f = fopen(buf, "r");
