Re: [libvirt] [PATCH 5/4] security: Don't try to lock NULL paths
On 9/25/18 3:34 AM, Michal Privoznik wrote:
It may happen that in the list of paths/disk sources to relabel
there is a disk source. If that is the case, the path is NULL. In
that case, we shouldn't try to lock the path. It's likely a
network disk anyway and therefore there is nothing to lock.
I think this needs a tweak to reference commit 6d855abc1 which only
filtered if the provided @p was a directory. This adds another filter
when @p is NULL such as would be the case with networked storage.
NB: The storage source is only passed for DAC and not selinux. The DAC
code makes a some valiant attempts at src->path if not Local too. The
selinux code has lots of branches and callers which seem to validly pass
a path, but I could have missed a path or some nuance.
The "key" is chasing virSecurityDACChownListAppend and
virSecuritySELinuxContextListAppend where the list->[n]items is
populated via VIR_APPEND_ELEMENT. Expect to spend some time on the chase!
You already have an R-by and I don't have anything else to provide on
this particular one other than yeah, better safe than sorry and passing
NULL. Although I have to imagine the stat(NULL, &s) in virFileIsDir
wouldn't have been pleased.
John
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/security/security_dac.c | 3 ++-
src/security/security_selinux.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/src/security/security_dac.c b/src/security/security_dac.c
index 876cca0f2f..04168feb3d 100644
--- a/src/security/security_dac.c
+++ b/src/security/security_dac.c
@@ -216,7 +216,8 @@ virSecurityDACTransactionRun(pid_t pid ATTRIBUTE_UNUSED,
for (i = 0; i < list->nItems; i++) {
const char *p = list->items[i]->path;
- if (virFileIsDir(p))
+ if (!p ||
+ virFileIsDir(p))
continue;
VIR_APPEND_ELEMENT_COPY_INPLACE(paths, npaths, p);
diff --git a/src/security/security_selinux.c b/src/security/security_selinux.c
index 3c847d8dcb..3adbeada14 100644
--- a/src/security/security_selinux.c
+++ b/src/security/security_selinux.c
@@ -227,7 +227,8 @@ virSecuritySELinuxTransactionRun(pid_t pid ATTRIBUTE_UNUSED,
for (i = 0; i < list->nItems; i++) {
const char *p = list->items[i]->path;
- if (virFileIsDir(p))
+ if (!p ||
+ virFileIsDir(p))
continue;
VIR_APPEND_ELEMENT_COPY_INPLACE(paths, npaths, p);