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When gntdev_ioctl_map_grant_ref() fails to copy the operation result back to userspace after successfully adding the mapping to the list, the error path returns -EFAULT without releasing the reference acquired by gntdev_alloc_map(). The mapping remains in priv->maps with a refcount of 1, causing a memory leak and a dangling list entry. Additionally, gntdev_add_map() may modify map->index to avoid overlap with existing mappings. Therefore, the index returned to userspace must be obtained after gntdev_add_map() completes. Fix this by holding the mutex across gntdev_add_map(), retrieving the correct index, and copy_to_user(). If copy_to_user() fails, remove the mapping from the list and release the reference while still holding the lock. Cc: stable@vger.kernel.org Fix these issues by properly handling all error cases. Fixes:1401c00e59("xen/gntdev: convert priv->lock to a mutex") Fixes:68b025c813("xen-gntdev: Add reference counting to maps") Signed-off-by: Wentao Liang <vulab@iscas.ac.cn> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Message-ID: <20260622112541.38194-1-vulab@iscas.ac.cn>
1198 lines
30 KiB
1198 lines
30 KiB