Commit e668d1b8 authored by zhanghailiang's avatar zhanghailiang Committed by Michael Roth
Browse files

qga: Rewrite code where using readdir_r 



If readdir_r fails, error_setg_errno will reference the freed
pointer *dirpath*.

Moreover, readdir_r may cause a buffer overflow, using readdir instead.

Signed-off-by: default avatarzhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: default avatarMichael Roth <mdroth@linux.vnet.ibm.com>
parent 01a2050f

qga/commands-posix.c

+15 −12
Original line number Diff line number Diff line
@@ -956,7 +956,7 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath, 
{

    DIR *dir;

    char *dirpath;

    struct dirent entry, *result;

    struct dirent *entry;



    dirpath = g_strdup_printf("%s/slaves", syspath);

    dir = opendir(dirpath);
@@ -965,22 +965,24 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath, 
        g_free(dirpath);

        return;

    }

    g_free(dirpath);



    for (;;) {

        if (readdir_r(dir, &entry, &result) != 0) {

            error_setg_errno(errp, errno, "readdir_r(\"%s\")", dirpath);

            break;

        errno = 0;

        entry = readdir(dir);

        if (entry == NULL) {

            if (errno) {

                error_setg_errno(errp, errno, "readdir(\"%s\")", dirpath);

            }

        if (!result) {

            break;

        }



        if (entry.d_type == DT_LNK) {

            g_debug(" slave device '%s'", entry.d_name);

            dirpath = g_strdup_printf("%s/slaves/%s", syspath, entry.d_name);

            build_guest_fsinfo_for_device(dirpath, fs, errp);

            g_free(dirpath);

        if (entry->d_type == DT_LNK) {

            char *path;



            g_debug(" slave device '%s'", entry->d_name);

            path = g_strdup_printf("%s/slaves/%s", syspath, entry->d_name);

            build_guest_fsinfo_for_device(path, fs, errp);

            g_free(path);



            if (*errp) {

                break;
@@ -988,6 +990,7 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath, 
        }

    }



    g_free(dirpath);

    closedir(dir);

}