From 89a8a2e9c4ab4d71020a6e8722066b6c2dc92904 Mon Sep 17 00:00:00 2001 From: Zhao Liu Date: Mon, 11 Mar 2024 11:38:13 +0800 Subject: [PATCH] hw/vfio/helpers: Fix missing ERRP_GUARD() for error_prepend() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As the comment in qapi/error, passing @errp to error_prepend() requires ERRP_GUARD(): * = Why, when and how to use ERRP_GUARD() = * * Without ERRP_GUARD(), use of the @errp parameter is restricted: ... * - It should not be passed to error_prepend(), error_vprepend() or * error_append_hint(), because that doesn't work with &error_fatal. * ERRP_GUARD() lifts these restrictions. * * To use ERRP_GUARD(), add it right at the beginning of the function. * @errp can then be used without worrying about the argument being * NULL or &error_fatal. ERRP_GUARD() could avoid the case when @errp is &error_fatal, the user can't see this additional information, because exit() happens in error_setg earlier than information is added [1]. In hw/vfio/helpers.c, there are 3 functions passing @errp to error_prepend() without ERRP_GUARD(): - vfio_set_irq_signaling() - vfio_device_get_name() - vfio_device_set_fd() There are too many possible callers to check the impact of this defect; it may or may not be harmless. Thus it is necessary to protect their @errp with ERRP_GUARD(). To avoid the issue like [1] said, add missing ERRP_GUARD() at their beginning. [1]: Issue description in the commit message of commit ae7c80a7bd73 ("error: New macro ERRP_GUARD()"). Cc: Alex Williamson Cc: Cédric Le Goater Signed-off-by: Zhao Liu Reviewed-by: Cédric Le Goater Message-ID: <20240311033822.3142585-21-zhao1.liu@linux.intel.com> Signed-off-by: Thomas Huth --- hw/vfio/helpers.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c index 6789870802..47b4096c05 100644 --- a/hw/vfio/helpers.c +++ b/hw/vfio/helpers.c @@ -110,6 +110,7 @@ static const char *index_to_str(VFIODevice *vbasedev, int index) int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex, int action, int fd, Error **errp) { + ERRP_GUARD(); struct vfio_irq_set *irq_set; int argsz, ret = 0; const char *name; @@ -613,6 +614,7 @@ bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type) int vfio_device_get_name(VFIODevice *vbasedev, Error **errp) { + ERRP_GUARD(); struct stat st; if (vbasedev->fd < 0) { @@ -644,6 +646,7 @@ int vfio_device_get_name(VFIODevice *vbasedev, Error **errp) void vfio_device_set_fd(VFIODevice *vbasedev, const char *str, Error **errp) { + ERRP_GUARD(); int fd = monitor_fd_param(monitor_cur(), str, errp); if (fd < 0) {