Re: [libvirt] [RFC PATCH 2/4] util: Fix deadlock across fork()

This commit fixes the deadlock introduced by commit 0980764dee687e8da86dc410c351759867163389. The call getgrouplist() of the glibc library isn't safe to be called in between fork and exec (see commit 75c125641ac73473ba4b0542524d67a184769c8e). Signed-off-by: Marc Hartmayer <mhartmay(a)linux.vnet.ibm.com&gt; Fixes: 0980764dee68 ("util: share code between virExec and virCommandExec") Reviewed-by: Bjoern Walk <bwalk(a)linux.vnet.ibm.com&gt; Reviewed-by: Boris Fiuczynski <fiuczy(a)linux.vnet.ibm.com&gt; --- src/lxc/lxc_container.c | 12 +++++++++++- src/util/vircommand.c | 25 ++++++++++++++----------- src/util/vircommand.h | 2 +- tests/commandtest.c | 15 ++++++++++----- 4 files changed, 36 insertions(+), 18 deletions(-) diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index ec6d6a86b0b6..1f220c602b0a 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -2182,6 +2182,8 @@ static int lxcContainerChild(void *data) virDomainFSDefPtr root; virCommandPtr cmd = NULL; int hasReboot; + gid_t *groups = NULL; + int ngroups; if (NULL == vmDef) { virReportError(VIR_ERR_INTERNAL_ERROR, @@ -2297,6 +2299,13 @@ static int lxcContainerChild(void *data) goto cleanup; } + /* TODO is it safe to call it here or should this call be moved in + * front of the clone() as otherwise there might be a risk for a + * deadlock */

+ if ((ngroups = virGetGroupList(virCommandGetUID(cmd), virCommandGetGID(cmd), + &groups)) < 0) + goto cleanup; + ret = 0; cleanup: VIR_FREE(ttyPath);