From bca7a53333ead7c1afd178728de74c2977cd4b5e Mon Sep 17 00:00:00 2001 From: Michal Privoznik Date: Mon, 31 Oct 2022 15:38:13 +0100 Subject: [PATCH] qemu_namespace: Don't leak memory in qemuDomainGetPreservedMounts() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The aim of qemuDomainGetPreservedMounts() is to get a list of filesystems mounted under /dev and optionally generate a path for each one where they are moved temporarily when building the namespace. And the function tries to be a bit clever about it. For instance, if /dev/shm mount point exists, there's no need to consider /dev/shm/a nor /dev/shm/b as preserving just 'top level' /dev/shm gives the same result. To achieve this, the function iterates over the list of filesystem as returned by virFileGetMountSubtree() and removes the nested ones. However, it does so in a bit clumsy way: plain VIR_DELETE_ELEMENT() is used without freeing the string itself. Therefore, if all three aforementioned example paths appeared on the list, /dev/shm/a and /dev/shm/b strings would be leaked. And when I think about it more, there's no real need to shrink the array down (realloc()). It's going to be free()-d when returning from the function. Switch to VIR_DELETE_ELEMENT_INPLACE() then. Fixes: cdd9205dfffa3aaed935446a41f0d2dd1357c268 Signed-off-by: Michal Privoznik Reviewed-by: Peter Krempa Reviewed-by: Ján Tomko --- src/qemu/qemu_namespace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_namespace.c b/src/qemu/qemu_namespace.c index 311c66d46e..9fed6871e8 100644 --- a/src/qemu/qemu_namespace.c +++ b/src/qemu/qemu_namespace.c @@ -159,7 +159,8 @@ qemuDomainGetPreservedMounts(virQEMUDriverConfig *cfg, if (c && (*c == '/' || *c == '\0')) { VIR_DEBUG("Dropping path %s because of %s", mounts[j], mounts[i]); - VIR_DELETE_ELEMENT(mounts, j, nmounts); + VIR_FREE(mounts[j]); + VIR_DELETE_ELEMENT_INPLACE(mounts, j, nmounts); } else { j++; }