From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DCBA599A3F for ; Tue, 8 Sep 2026 22:37:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788907039; cv=none; b=JtjDrikT58+rQdkPqWv+I/H90gPozxGseHrGr0qUJ1ot6V8GVncEilpVpwY+WCx48gubzRqYI7ITDcsbZJk97LrGEjC6YqC4j6TfFKRFVOHA2MxvprhXcAwwmSLmrRaT6BcnohWltDN16PVC22po2NWFlnNXFMnu+SUGpeMpKxA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788907039; c=relaxed/simple; bh=MXiAdolEoNBHC3m1AXg9RAwW+erHKPZI/4qZu7Zlids=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QA1QP/vwX0uYM3k2V1xXVff+TObfP1y6dpmKYZQkTJh7X+ITe+aVYRzRoBucl156bGHCYAjvBvR6nsj83vEpFLjrcLqQXwysOIiq7crhdvuBV6O6heksCcbtF7Hi4Yt7N6H0QKZOi+o+f3zWwzkMRpGcWzLXZqNXfhdI9csxfJA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Xbvq8vxL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Xbvq8vxL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89A781F00A3A; Tue, 8 Sep 2026 22:37:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788907037; bh=XuHWGfALNdYzZjEt44j+7jyX+nj3Qosxxa+S4yPZopA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Xbvq8vxLJoAIozXocJ9+GTNrY22oQF5sEg/28HqFA2fxlx+SEiGDx+ypbR03fGwG3 eLIf0vVIl36Cw5HxH5bXavoor1bWo/AeUZzTZneRukVYjb39zFImMldWiSPubxyqO1 zoPughp5pHXRP7TMTASmhvohQuik2mhOYosH2WfhpVp9CYyCMNgL/uUb2GzDD7X978 i8ChJVC//GSCMg0L0V5VwLn2XhncNy0DvHSnOcENtx+5TzPFqnRUgalXh79Og7I5UA kUTuRB9PSLpRqXBTnBl2ztmtqBqPIeCnSt9aeToIxK/K0nRDq6u0MjST8sC3BJqBcM yZ5A3sBqHaUVQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Al Viro , Jeff Layton , Sasha Levin Subject: [PATCH 6.12.y 1/4] rpc_populate(): lift cleanup into callers Date: Tue, 8 Sep 2026 18:37:12 -0400 Message-ID: <20260908223715.507115-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026090317-curled-track-17d1@gregkh> References: <2026090317-curled-track-17d1@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Al Viro [ Upstream commit 8be22c49646e47452e74aa0b97ea50fb04c271ed ] rpc_populate() is called either from fill_super (where we don't need to remove any files on failure - rpc_kill_sb() will take them all out anyway) or from rpc_mkdir_populate(), where we need to remove the directory we'd been trying to populate along with whatever we'd put into it before we failed. Simpler to combine that into simple_recursive_removal() there. Note that rpc_pipe is overlocking directories quite a bit - locked parent is no obstacle to finding a child in dcache, so keeping it locked won't prevent userland observing a partially built subtree. All we need is to follow minimal VFS requirements; it's not as if clients used directory locking for exclusion - tree changes are serialized, but that's done on ->pipefs_sb_lock. Reviewed-by: Jeff Layton Signed-off-by: Al Viro Stable-dep-of: 932a8cf6abb2 ("sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir") Signed-off-by: Sasha Levin --- include/linux/sunrpc/rpc_pipe_fs.h | 2 +- net/sunrpc/clnt.c | 36 ++++++++++++------------------ net/sunrpc/rpc_pipe.c | 26 ++++++++++----------- 3 files changed, 28 insertions(+), 36 deletions(-) diff --git a/include/linux/sunrpc/rpc_pipe_fs.h b/include/linux/sunrpc/rpc_pipe_fs.h index 3b35b6f6533aa..f4b9ea5c83ea1 100644 --- a/include/linux/sunrpc/rpc_pipe_fs.h +++ b/include/linux/sunrpc/rpc_pipe_fs.h @@ -98,7 +98,7 @@ static inline bool rpc_msg_is_inflight(const struct rpc_pipe_msg *msg) { } struct rpc_clnt; -extern struct dentry *rpc_create_client_dir(struct dentry *, const char *, struct rpc_clnt *); +extern int rpc_create_client_dir(struct dentry *, const char *, struct rpc_clnt *); extern int rpc_remove_client_dir(struct rpc_clnt *); extern void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh); diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index e88e21c2ab329..1eca77bd03930 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -112,47 +112,46 @@ static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt) } } -static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb, +static int rpc_setup_pipedir_sb(struct super_block *sb, struct rpc_clnt *clnt) { static uint32_t clntid; const char *dir_name = clnt->cl_program->pipe_dir_name; char name[15]; - struct dentry *dir, *dentry; + struct dentry *dir; + int err; dir = rpc_d_lookup_sb(sb, dir_name); if (dir == NULL) { pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name); - return dir; + return -ENOENT; } for (;;) { snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++); name[sizeof(name) - 1] = '\0'; - dentry = rpc_create_client_dir(dir, name, clnt); - if (!IS_ERR(dentry)) + err = rpc_create_client_dir(dir, name, clnt); + if (!err) break; - if (dentry == ERR_PTR(-EEXIST)) + if (err == -EEXIST) continue; printk(KERN_INFO "RPC: Couldn't create pipefs entry" - " %s/%s, error %ld\n", - dir_name, name, PTR_ERR(dentry)); + " %s/%s, error %d\n", + dir_name, name, err); break; } dput(dir); - return dentry; + return err; } static int rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt) { - struct dentry *dentry; - clnt->pipefs_sb = pipefs_sb; if (clnt->cl_program->pipe_dir_name != NULL) { - dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt); - if (IS_ERR(dentry)) - return PTR_ERR(dentry); + int err = rpc_setup_pipedir_sb(pipefs_sb, clnt); + if (err && err != -ENOENT) + return err; } return 0; } @@ -180,16 +179,9 @@ static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event) static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event, struct super_block *sb) { - struct dentry *dentry; - switch (event) { case RPC_PIPEFS_MOUNT: - dentry = rpc_setup_pipedir_sb(sb, clnt); - if (!dentry) - return -ENOENT; - if (IS_ERR(dentry)) - return PTR_ERR(dentry); - break; + return rpc_setup_pipedir_sb(sb, clnt); case RPC_PIPEFS_UMOUNT: __rpc_clnt_remove_pipedir(clnt); break; diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c index eadc00410ebc5..43119907010e3 100644 --- a/net/sunrpc/rpc_pipe.c +++ b/net/sunrpc/rpc_pipe.c @@ -725,7 +725,6 @@ static int rpc_populate(struct dentry *parent, inode_unlock(dir); return 0; out_bad: - __rpc_depopulate(parent, files, start, eof); inode_unlock(dir); printk(KERN_WARNING "%s: %s failed to populate directory %pd\n", __FILE__, __func__, parent); @@ -749,14 +748,15 @@ static struct dentry *rpc_mkdir_populate(struct dentry *parent, goto out_err; if (populate != NULL) { error = populate(dentry, args_populate); - if (error) - goto err_rmdir; + if (error) { + inode_unlock(dir); + simple_recursive_removal(dentry, NULL); + return ERR_PTR(error); + } } out: inode_unlock(dir); return dentry; -err_rmdir: - __rpc_rmdir(dir, dentry); out_err: dentry = ERR_PTR(error); goto out; @@ -1046,19 +1046,19 @@ static void rpc_clntdir_depopulate(struct dentry *dentry) * information about the client, together with any "pipes" that may * later be created using rpc_mkpipe(). */ -struct dentry *rpc_create_client_dir(struct dentry *dentry, - const char *name, - struct rpc_clnt *rpc_client) +int rpc_create_client_dir(struct dentry *dentry, + const char *name, + struct rpc_clnt *rpc_client) { struct dentry *ret; ret = rpc_mkdir_populate(dentry, name, 0555, NULL, rpc_clntdir_populate, rpc_client); - if (!IS_ERR(ret)) { - rpc_client->cl_pipedir_objects.pdh_dentry = ret; - rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects); - } - return ret; + if (IS_ERR(ret)) + return PTR_ERR(ret); + rpc_client->cl_pipedir_objects.pdh_dentry = ret; + rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects); + return 0; } /** -- 2.53.0