Since atm we don't take a reference on the dma buf pointer when we add it to the import lookup table the dma buf can vanish leaving the stale pointer behind. This can in turn lead to returning stale GEM handles when userspace imports a newly exported buffer.
Fix this by keeping a reference on the dma buffer whenever we have a pointer to it in the lookup table. Reference: https://bugs.freedesktop.org/show_bug.cgi?id=59229 Signed-off-by: Imre Deak <imre.deak at intel.com> --- drivers/gpu/drm/drm_prime.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index bba45f6..e4e1a69 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -501,6 +501,7 @@ int drm_prime_add_imported_buf_handle(struct drm_prime_file_private *prime_fpriv if (!member) return -ENOMEM; + get_dma_buf(dma_buf); member->dma_buf = dma_buf; member->handle = handle; list_add(&member->entry, &prime_fpriv->head); @@ -529,6 +530,7 @@ void drm_prime_remove_imported_buf_handle(struct drm_prime_file_private *prime_f mutex_lock(&prime_fpriv->lock); list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { if (member->dma_buf == dma_buf) { + dma_buf_put(dma_buf); list_del(&member->entry); kfree(member); } -- 1.7.10.4
