[libvirt] [PATCH] Avoid crash on NULL pointer in lock driver impls during hotplug

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; When virLockDriverAcquire is invoked during hotplug the state parameter will be left as NULL. * src/locking/lock_driver_nop.c, src/locking/lock_driver_sanlock.c: Don't reference NULL state parameter --- src/locking/lock_driver_nop.c | 7 ++++--- src/locking/lock_driver_sanlock.c | 29 ++++++++++++++++++----------- 2 files changed, 22 insertions(+), 14 deletions(-) diff --git a/src/locking/lock_driver_nop.c b/src/locking/lock_driver_nop.c index 5ebbd8d..36a9083 100644 --- a/src/locking/lock_driver_nop.c +++ b/src/locking/lock_driver_nop.c @@ -76,7 +76,8 @@ static int virLockManagerNopRelease(virLockManagerPtr lock ATTRIBUTE_UNUSED, char **state, unsigned int flags ATTRIBUTE_UNUSED) { - *state = NULL; + if (state) + *state = NULL; return 0; } @@ -85,8 +86,8 @@ static int virLockManagerNopInquire(virLockManagerPtr lock ATTRIBUTE_UNUSED, char **state, unsigned int flags ATTRIBUTE_UNUSED) { - - *state = NULL; + if (state) + *state = NULL; return 0; } diff --git a/src/locking/lock_driver_sanlock.c b/src/locking/lock_driver_sanlock.c index a60d7ce..adead76 100644 --- a/src/locking/lock_driver_sanlock.c +++ b/src/locking/lock_driver_sanlock.c @@ -374,18 +374,20 @@ static int virLockManagerSanlockRelease(virLockManagerPtr lock, virCheckFlags(0, -1); - if ((rv = sanlock_inquire(-1, priv->vm_pid, 0, &res_count, state)) < 0) { - if (rv <= -200) - virLockError(VIR_ERR_INTERNAL_ERROR, - _("Failed to inquire lock: error %d"), rv); - else - virReportSystemError(-rv, "%s", - _("Failed to inquire lock")); - return -1; - } + if (state) { + if ((rv = sanlock_inquire(-1, priv->vm_pid, 0, &res_count, state)) < 0) { + if (rv <= -200) + virLockError(VIR_ERR_INTERNAL_ERROR, + _("Failed to inquire lock: error %d"), rv); + else + virReportSystemError(-rv, "%s", + _("Failed to inquire lock")); + return -1; + } - if (STREQ(*state, "")) - VIR_FREE(*state); + if (STREQ(*state, "")) + VIR_FREE(*state); + } if ((rv = sanlock_release(-1, priv->vm_pid, SANLK_REL_ALL, 0, NULL)) < 0) { if (rv <= -200) @@ -409,6 +411,11 @@ static int virLockManagerSanlockInquire(virLockManagerPtr lock, virCheckFlags(0, -1); + if (!state) { + virLockError(VIR_ERR_INVALID_ARG, "state"); + return -1; + } + VIR_DEBUG("pid=%d", priv->vm_pid); if ((rv = sanlock_inquire(-1, priv->vm_pid, 0, &res_count, state)) < 0) { -- 1.7.5.2