FAILED: Patch "SUNRPC: auth_gss: fix memory leaks in XDR decoding error paths" failed to apply to 6.12-stable tree
From: Sasha Levin <sashal@kernel.org>
Date: 2026-03-01 01:24:16
Also in:
linux-nfs, stable
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to [off-list ref].
Thanks,
Sasha
------------------ original commit in Linus's tree ------------------
From 3e6397b056335cc56ef0e9da36c95946a19f5118 Mon Sep 17 00:00:00 2001
From: Chuck Lever <redacted>
Date: Fri, 26 Dec 2025 10:15:32 -0500
Subject: [PATCH] SUNRPC: auth_gss: fix memory leaks in XDR decoding error
paths
The gssx_dec_ctx(), gssx_dec_status(), and gssx_dec_name()
functions allocate memory via gssx_dec_buffer(), which calls
kmemdup(). When a subsequent decode operation fails, these
functions return immediately without freeing previously
allocated buffers, causing memory leaks.
The leak in gssx_dec_ctx() is particularly relevant because
the caller (gssp_accept_sec_context_upcall) initializes several
buffer length fields to non-zero values, resulting in memory
allocation:
struct gssx_ctx rctxh = {
.exported_context_token.len = GSSX_max_output_handle_sz,
.mech.len = GSS_OID_MAX_LEN,
.src_name.display_name.len = GSSX_max_princ_sz,
.targ_name.display_name.len = GSSX_max_princ_sz
};
If, for example, gssx_dec_name() succeeds for src_name but
fails for targ_name, the memory allocated for
exported_context_token, mech, and src_name.display_name
remains unreferenced and cannot be reclaimed.
Add error handling with goto-based cleanup to free any
previously allocated buffers before returning an error.
Reported-by: Xingjing Deng <redacted>
Closes: https://lore.kernel.org/linux-nfs/CAK+ZN9qttsFDu6h1FoqGadXjMx1QXqPMoYQ=6O9RY4SxVTvKng@mail.gmail.com/ (local)
Fixes: 1d658336b05f ("SUNRPC: Add RPC based upcall mechanism for RPCGSS auth")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <redacted>
---
net/sunrpc/auth_gss/gss_rpc_xdr.c | 82 ++++++++++++++++++++++++-------
1 file changed, 64 insertions(+), 18 deletions(-)
diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
index 7d2cdc2bd374e..f320c0a8e6049 100644
--- a/net/sunrpc/auth_gss/gss_rpc_xdr.c
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c@@ -320,29 +320,47 @@ static int gssx_dec_status(struct xdr_stream *xdr, /* status->minor_status */ p = xdr_inline_decode(xdr, 8); - if (unlikely(p == NULL)) - return -ENOSPC; + if (unlikely(p == NULL)) { + err = -ENOSPC; + goto out_free_mech; + } p = xdr_decode_hyper(p, &status->minor_status); /* status->major_status_string */ err = gssx_dec_buffer(xdr, &status->major_status_string); if (err) - return err; + goto out_free_mech; /* status->minor_status_string */ err = gssx_dec_buffer(xdr, &status->minor_status_string); if (err) - return err; + goto out_free_major_status_string; /* status->server_ctx */ err = gssx_dec_buffer(xdr, &status->server_ctx); if (err) - return err; + goto out_free_minor_status_string; /* we assume we have no options for now, so simply consume them */ /* status->options */ err = dummy_dec_opt_array(xdr, &status->options); + if (err) + goto out_free_server_ctx; + return 0; + +out_free_server_ctx: + kfree(status->server_ctx.data); + status->server_ctx.data = NULL; +out_free_minor_status_string: + kfree(status->minor_status_string.data); + status->minor_status_string.data = NULL; +out_free_major_status_string: + kfree(status->major_status_string.data); + status->major_status_string.data = NULL; +out_free_mech: + kfree(status->mech.data); + status->mech.data = NULL; return err; }
@@ -505,28 +523,35 @@ static int gssx_dec_name(struct xdr_stream *xdr, /* name->name_type */ err = gssx_dec_buffer(xdr, &dummy_netobj); if (err) - return err; + goto out_free_display_name; /* name->exported_name */ err = gssx_dec_buffer(xdr, &dummy_netobj); if (err) - return err; + goto out_free_display_name; /* name->exported_composite_name */ err = gssx_dec_buffer(xdr, &dummy_netobj); if (err) - return err; + goto out_free_display_name; /* we assume we have no attributes for now, so simply consume them */ /* name->name_attributes */ err = dummy_dec_nameattr_array(xdr, &dummy_name_attr_array); if (err) - return err; + goto out_free_display_name; /* we assume we have no options for now, so simply consume them */ /* name->extensions */ err = dummy_dec_opt_array(xdr, &dummy_option_array); + if (err) + goto out_free_display_name; + return 0; + +out_free_display_name: + kfree(name->display_name.data); + name->display_name.data = NULL; return err; }
@@ -649,32 +674,34 @@ static int gssx_dec_ctx(struct xdr_stream *xdr, /* ctx->state */ err = gssx_dec_buffer(xdr, &ctx->state); if (err) - return err; + goto out_free_exported_context_token; /* ctx->need_release */ err = gssx_dec_bool(xdr, &ctx->need_release); if (err) - return err; + goto out_free_state; /* ctx->mech */ err = gssx_dec_buffer(xdr, &ctx->mech); if (err) - return err; + goto out_free_state; /* ctx->src_name */ err = gssx_dec_name(xdr, &ctx->src_name); if (err) - return err; + goto out_free_mech; /* ctx->targ_name */ err = gssx_dec_name(xdr, &ctx->targ_name); if (err) - return err; + goto out_free_src_name; /* ctx->lifetime */ p = xdr_inline_decode(xdr, 8+8); - if (unlikely(p == NULL)) - return -ENOSPC; + if (unlikely(p == NULL)) { + err = -ENOSPC; + goto out_free_targ_name; + } p = xdr_decode_hyper(p, &ctx->lifetime); /* ctx->ctx_flags */
@@ -683,17 +710,36 @@ static int gssx_dec_ctx(struct xdr_stream *xdr, /* ctx->locally_initiated */ err = gssx_dec_bool(xdr, &ctx->locally_initiated); if (err) - return err; + goto out_free_targ_name; /* ctx->open */ err = gssx_dec_bool(xdr, &ctx->open); if (err) - return err; + goto out_free_targ_name; /* we assume we have no options for now, so simply consume them */ /* ctx->options */ err = dummy_dec_opt_array(xdr, &ctx->options); + if (err) + goto out_free_targ_name; + + return 0; +out_free_targ_name: + kfree(ctx->targ_name.display_name.data); + ctx->targ_name.display_name.data = NULL; +out_free_src_name: + kfree(ctx->src_name.display_name.data); + ctx->src_name.display_name.data = NULL; +out_free_mech: + kfree(ctx->mech.data); + ctx->mech.data = NULL; +out_free_state: + kfree(ctx->state.data); + ctx->state.data = NULL; +out_free_exported_context_token: + kfree(ctx->exported_context_token.data); + ctx->exported_context_token.data = NULL; return err; }
--
2.51.0