Re: [libvirt] [PATCH] cpu: fix possible crash in getModels

Commit 86a15a25 introduced a new cpu driver API 'getModels'. Public API allow you to pass NULL for models to get only number of existing models. However the new code will crash with segfault so we have to count with the possibility that the user wants only the number. There is also difference in order of the models gathered by this new API as the old approach was inserting the elements to the end of the array so we should use 'VIR_APPEND_ELEMENT'. Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; --- src/cpu/cpu_powerpc.c | 15 ++++++++++----- src/cpu/cpu_x86.c | 15 ++++++++++----- 2 files changed, 20 insertions(+), 10 deletions(-) diff --git a/src/cpu/cpu_powerpc.c b/src/cpu/cpu_powerpc.c index 871401b..86f80b3 100644 --- a/src/cpu/cpu_powerpc.c +++ b/src/cpu/cpu_powerpc.c @@ -666,11 +666,15 @@ ppcGetModels(char ***models) model = map->models; while (model != NULL) { - if (VIR_STRDUP(name, model->name) < 0) - goto error; + if (models) { + if (VIR_STRDUP(name, model->name) < 0) + goto error; - if (VIR_INSERT_ELEMENT(*models, 0, nmodels, name) < 0) - goto error; + if (VIR_APPEND_ELEMENT(*models, nmodels, name) < 0) + goto error; + } else { + nmodels++; + } model = model->next; } @@ -681,7 +685,8 @@ ppcGetModels(char ***models) return nmodels; error: - virStringFreeList(*models); + if (models) + virStringFreeList(*models);

nmodels = -1; goto cleanup; } diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c index f6dcba4..dfbc16c 100644 --- a/src/cpu/cpu_x86.c +++ b/src/cpu/cpu_x86.c @@ -2176,11 +2176,15 @@ x86GetModels(char ***models) model = map->models; while (model != NULL) { - if (VIR_STRDUP(name, model->name) < 0) - goto error; + if (models) { + if (VIR_STRDUP(name, model->name) < 0) + goto error; - if (VIR_INSERT_ELEMENT(*models, 0, nmodels, name) < 0) - goto error; + if (VIR_APPEND_ELEMENT(*models, nmodels, name) < 0) + goto error; + } else { + nmodels++; + } model = model->next; } @@ -2188,7 +2192,8 @@ x86GetModels(char ***models) return nmodels; error: - virStringFreeList(*models); + if (models) + virStringFreeList(*models);

return -1; }