From 447655089ea0ed9ded07131fb7443ae483fd1b07 Mon Sep 17 00:00:00 2001 From: Zhao Liu Date: Mon, 11 Mar 2024 11:38:15 +0800 Subject: [PATCH] hw/vfio/pci-quirks: 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/pci-quirks.c, there are 2 functions passing @errp to error_prepend() without ERRP_GUARD(): - vfio_add_nv_gpudirect_cap() - vfio_add_vmd_shadow_cap() 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 the beginning of this function. [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: <20240311033822.3142585-23-zhao1.liu@linux.intel.com> Signed-off-by: Thomas Huth --- hw/vfio/pci-quirks.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c index 84b1a7b948..496fd1ee86 100644 --- a/hw/vfio/pci-quirks.c +++ b/hw/vfio/pci-quirks.c @@ -1538,6 +1538,7 @@ static bool is_valid_std_cap_offset(uint8_t pos) static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp) { + ERRP_GUARD(); PCIDevice *pdev = &vdev->pdev; int ret, pos; bool c8_conflict = false, d4_conflict = false; @@ -1630,6 +1631,7 @@ static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp) #define VMD_SHADOW_CAP_LEN 24 static int vfio_add_vmd_shadow_cap(VFIOPCIDevice *vdev, Error **errp) { + ERRP_GUARD(); uint8_t membar_phys[16]; int ret, pos = 0xE8;