Fix memory leak of remote context in gpp_remote_to_local_ctx - #131
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When converting a remote (gssproxy-side) context to a local one, gpp_remote_to_local_ctx() called xdr_free() on *remote_ctx to release the members of the gssx_ctx, but never free()'d the gssx_ctx struct itself before clearing the pointer. The struct is allocated by the XDR layer (gssrpc_xdr_reference) when decoding the init_sec_context reply, so this orphaned one gssx_ctx allocation on every conversion. This is hit on every successful sec=krb5 mount: gssd serializes the context for the kernel via gss_export_lucid_sec_context(), which the mechglue dispatches into gssi_inquire_sec_context_by_oid() -> gpp_remote_to_local_ctx(), leaking the remote context each time. Add the missing free(*remote_ctx), matching the xdr_free()+free() pattern already used in gpm_delete_sec_context(). This fixes the following leak: ==1043== 576 bytes in 2 blocks are definitely lost in loss record 815 of 926 ==1043== at 0x4877826: malloc (vg_replace_malloc.c:447) ==1043== by 0x5774BC1: gssrpc_xdr_reference (in /usr/lib64/libgssrpc.so.4.2) ==1043== by 0x5725E27: xdr_gssx_res_init_sec_context (gss_proxy_xdr.c:577) ==1043== by 0x5728512: gpm_make_call (gpm_common.c:768) ==1043== by 0x572BC83: gpm_init_sec_context (gpm_init_sec_context.c:94) ==1043== by 0x5731B83: gssi_init_sec_context (gpp_init_sec_context.c:158) ==1043== by 0x48F1C62: gss_init_sec_context (in /usr/lib64/libgssapi_krb5.so.2.2) ==1043== by 0x4A43DED: _rpc_gss_refresh (auth_gss.c:484) ==1043== by 0x4A44A79: rpc_gss_seccreate (auth_gss.c:861) ==1043== by 0x4010674: create_auth_rpc_client.constprop.0 (gssd_proc.c:439) ==1043== by 0x4012C03: krb5_use_machine_creds (gssd_proc.c:660) ==1043== by 0x4012C03: process_krb5_upcall (gssd_proc.c:789) ==1043== by 0x4012C03: gssd_work_thread_fn (gssd_proc.c:932) ==1043== by 0x4B649E1: start_thread (in /usr/lib64/libc.so.6) ==1043== Assisted-by: Claude Opus 4.8 <noreply@anthropic.com> Signed-off-by: Scott Mayhew <smayhew@redhat.com>
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When converting a remote (gssproxy-side) context to a local one, gpp_remote_to_local_ctx() called xdr_free() on *remote_ctx to release the members of the gssx_ctx, but never free()'d the gssx_ctx struct itself before clearing the pointer. The struct is allocated by the XDR layer (gssrpc_xdr_reference) when decoding the init_sec_context reply, so this orphaned one gssx_ctx allocation on every conversion.
This is hit on every successful sec=krb5 mount: gssd serializes the context for the kernel via gss_export_lucid_sec_context(), which the mechglue dispatches into gssi_inquire_sec_context_by_oid() -> gpp_remote_to_local_ctx(), leaking the remote context each time.
Add the missing free(*remote_ctx), matching the xdr_free()+free() pattern already used in gpm_delete_sec_context().
This fixes the following leak:
==1043== 576 bytes in 2 blocks are definitely lost in loss record 815 of 926
==1043== at 0x4877826: malloc (vg_replace_malloc.c:447)
==1043== by 0x5774BC1: gssrpc_xdr_reference (in /usr/lib64/libgssrpc.so.4.2)
==1043== by 0x5725E27: xdr_gssx_res_init_sec_context (gss_proxy_xdr.c:577)
==1043== by 0x5728512: gpm_make_call (gpm_common.c:768)
==1043== by 0x572BC83: gpm_init_sec_context (gpm_init_sec_context.c:94)
==1043== by 0x5731B83: gssi_init_sec_context (gpp_init_sec_context.c:158)
==1043== by 0x48F1C62: gss_init_sec_context (in /usr/lib64/libgssapi_krb5.so.2.2)
==1043== by 0x4A43DED: _rpc_gss_refresh (auth_gss.c:484)
==1043== by 0x4A44A79: rpc_gss_seccreate (auth_gss.c:861)
==1043== by 0x4010674: create_auth_rpc_client.constprop.0 (gssd_proc.c:439)
==1043== by 0x4012C03: krb5_use_machine_creds (gssd_proc.c:660)
==1043== by 0x4012C03: process_krb5_upcall (gssd_proc.c:789)
==1043== by 0x4012C03: gssd_work_thread_fn (gssd_proc.c:932)
==1043== by 0x4B649E1: start_thread (in /usr/lib64/libc.so.6)
==1043==
Assisted-by: Claude Opus 4.8 noreply@anthropic.com