A potential memory leak exists in the gssx_dec_status function (in net/sunrpc/auth_gss/gss_rpc_xdr.c) and its dependent gssx_dec_buffer function. The leak occurs when gssx_dec_buffer allocates memory via kmemdup for gssx_buffer fields, but the allocated memory is not freed in error paths of the chained decoding process in gssx_dec_status.

The gssx_dec_buffer function allocates memory using kmemdup when buf->data is NULL (to store decoded XDR buffer data). This allocation is not paired with a release mechanism in case of subsequent decoding failures. gssx_dec_status sequentially decodes multiple gssx_buffer fields (e.g., mech, major_status_string, minor_status_string, server_ctx) by calling gssx_dec_buffer. If a later decoding step fails (e.g., gssx_dec_buffer returns -ENOSPC or -ENOMEM), the function immediately returns the error without freeing the memory allocated for earlier gssx_buffer fields. This results in persistent kernel memory leaks.

This memory allocation is conditional. I traced upward through the callers gssx_dec_status and found that it is ultimately invoked by the interface gssx_dec_accept_sec_context. Although I have not identified the specific code execution path that triggers this memory leak, I believe this coding pattern is highly prone to causing confusion between callers and callees, which in turn leads to memory leaks.

Relevant code links: https://github.com/torvalds/linux/blob/ccd1cdca5cd433c8a5dff78b69a79b31d9b77... https://github.com/torvalds/linux/blob/ccd1cdca5cd433c8a5dff78b69a79b31d9b77...

I have searched Bugzilla, lore.kernel.org, and client.linux-nfs.org, but no related issues were found.