[libvirt] [PATCH] util: only fchown newly created files in virFileOpenAs

virFileOpenAs takes desired uid:gid as arguments, and not only uses them for a fork/setuid/setgid when retrying failed open operations, but additionally always forces the opened file to be owned by the given uid:gid. One example of the problems this causes is that, when restoring a domain from a file that is owned by the qemu user, opening the file chowns it to root. if dynamic_ownership=1 this is coincidentally expected, but if dynamic_ownership=0, no existing file should ever have its ownership changed. This patch adds an extra check before calling fchown() - it only does it if O_CREAT was passed to virFileOpenAs() in the openflags. --- src/util/util.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/src/util/util.c b/src/util/util.c index b278165..9556bdb 100644 --- a/src/util/util.c +++ b/src/util/util.c @@ -697,6 +697,7 @@ virFileOpenAsNoFork(const char *path, int openflags, mode_t mode, goto error; } if (((st.st_uid != uid) || (st.st_gid != gid)) + && (openflags & O_CREAT) && (fchown(fd, uid, gid) < 0)) { ret = -errno; virReportSystemError(errno, _("cannot chown '%s' to (%u, %u)"), -- 1.7.3.4