[PATCH 6.12 1085/1102] rpc_populate(): lift cleanup into callers
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COLD22d
REVIEWED: 4 (4M)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2026-09-17 19:03:14
Also in:
linux-patches
1 review trailer.
6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Al Viro <viro@zeniv.linux.org.uk>
[ 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 <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Stable-dep-of: 932a8cf6abb2 ("sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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(-)
--- 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(c } 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); --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c
@@ -112,47 +112,46 @@ static void rpc_clnt_remove_pipedir(stru } } -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 rp 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; --- a/net/sunrpc/rpc_pipe.c +++ b/net/sunrpc/rpc_pipe.c
@@ -725,7 +725,6 @@ static int rpc_populate(struct dentry *p 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 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(struc * 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; } /**