Re: [libvirt] [PATCH 08/10] qemuDomainCreateDevice: Don't loop endlessly

When working with symlinks it is fairly easy to get into a loop. Don't. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_domain.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 8cbfb2d16..448583313 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -6954,9 +6954,10 @@ qemuDomainGetPreservedMounts(virQEMUDriverPtr driver, static int -qemuDomainCreateDevice(const char *device, - const char *path, - bool allow_noent) +qemuDomainCreateDeviceRecursive(const char *device, + const char *path, + bool allow_noent, + unsigned int ttl) { char *devicePath = NULL; char *target = NULL; @@ -6968,6 +6969,13 @@ qemuDomainCreateDevice(const char *device, char *tcon = NULL; #endif + if (!ttl) { + virReportSystemError(ELOOP, + _("Too many levels of symbolic links: %s"), + device); + return ret; + } + if (lstat(device, &sb) < 0) { if (errno == ENOENT && allow_noent) { /* Ignore non-existent device. */ @@ -7057,7 +7065,8 @@ qemuDomainCreateDevice(const char *device, tmp = NULL; } - if (qemuDomainCreateDevice(target, path, allow_noent) < 0) + if (qemuDomainCreateDeviceRecursive(target, path, + allow_noent, ttl - 1) < 0) goto cleanup; } else { if (create && @@ -7128,6 +7137,17 @@ qemuDomainCreateDevice(const char *device, } +static int +qemuDomainCreateDevice(const char *device, + const char *path, + bool allow_noent) +{ + long symloop_max = sysconf(_SC_SYMLOOP_MAX); + + return qemuDomainCreateDeviceRecursive(device, path, + allow_noent, symloop_max);

+} + static int qemuDomainPopulateDevices(virQEMUDriverPtr driver, -- 2.11.0 -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list