On Wed, Sep 06, 2023 at 06:34:42PM +0300, Dmitry Frolov wrote:
Reviewing the sources, I found, that
in function lxcContainerMountAllFS() pointers
vmDef->fss[i]->src and vmDef->fss[i]->src->path
are checked for NULL after dereferencing in
VIR_DEBUG() macro.
Fixes: 57487085dc ("lxc: don't try to reference NULL when mounting filesystems")
---
src/lxc/lxc_container.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index 21220661f7..58a6695458 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -1467,13 +1467,15 @@ static int lxcContainerMountAllFS(virDomainDef *vmDef,
if (STREQ(vmDef->fss[i]->dst, "/"))
continue;
+ if (!(vmDef->fss[i]->src && vmDef->fss[i]->src->path))
+ return -1;
+
This unfortunately changes the semantics. This fails whenever there is src or src->path missing, but ...
VIR_DEBUG("Mounting '%s' -> '%s'", vmDef->fss[i]->src->path, vmDef->fss[i]->dst);
if (lxcContainerResolveSymlinks(vmDef->fss[i], false) < 0)
return -1;
- if (!(vmDef->fss[i]->src && vmDef->fss[i]->src->path &&
- STRPREFIX(vmDef->fss[i]->src->path, vmDef->fss[i]->dst)) &&
+ if (!STRPREFIX(vmDef->fss[i]->src->path, vmDef->fss[i]->dst) &&
lxcContainerUnmountSubtree(vmDef->fss[i]->dst, false) < 0)
... here it only skips the unmount in such case. That makes sense because for example tmpfs does not have a source path, only the destination and the mount that is not visible in the context here would not only be skipped as well, but the whole starting of a domain would fail. Instead of this patch, you could just conditionally change the VIR_DEBUG() to report what's actually happening.
return -1;
--
2.34.1
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