--- /dev/null
+From a360f311f57a36e96d88fa8086b749159714dcd2 Mon Sep 17 00:00:00 2001
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Date: Mon, 21 Oct 2024 11:57:38 -0700
+Subject: 9p: fix slab cache name creation for real
+
+From: Linus Torvalds <torvalds@linux-foundation.org>
+
+commit a360f311f57a36e96d88fa8086b749159714dcd2 upstream.
+
+This was attempted by using the dev_name in the slab cache name, but as
+Omar Sandoval pointed out, that can be an arbitrary string, eg something
+like "/dev/root". Which in turn trips verify_dirent_name(), which fails
+if a filename contains a slash.
+
+So just make it use a sequence counter, and make it an atomic_t to avoid
+any possible races or locking issues.
+
+Reported-and-tested-by: Omar Sandoval <osandov@fb.com>
+Link: https://lore.kernel.org/all/ZxafcO8KWMlXaeWE@telecaster.dhcp.thefacebook.com/
+Fixes: 79efebae4afc ("9p: Avoid creating multiple slab caches with the same name")
+Acked-by: Vlastimil Babka <vbabka@suse.cz>
+Cc: Dominique Martinet <asmadeus@codewreck.org>
+Cc: Thorsten Leemhuis <regressions@leemhuis.info>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/9p/client.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+--- a/net/9p/client.c
++++ b/net/9p/client.c
+@@ -1003,6 +1003,7 @@ error:
+ struct p9_client *p9_client_create(const char *dev_name, char *options)
+ {
+ int err;
++ static atomic_t seqno = ATOMIC_INIT(0);
+ struct p9_client *clnt;
+ char *client_id;
+ char *cache_name;
+@@ -1058,7 +1059,8 @@ struct p9_client *p9_client_create(const
+ if (err)
+ goto close_trans;
+
+- cache_name = kasprintf(GFP_KERNEL, "9p-fcall-cache-%s", dev_name);
++ cache_name = kasprintf(GFP_KERNEL,
++ "9p-fcall-cache-%u", atomic_inc_return(&seqno));
+ if (!cache_name) {
+ err = -ENOMEM;
+ goto close_trans;