The patch below does not apply to the 6.10-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 stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.10.y git checkout FETCH_HEAD git cherry-pick -x 74c2ab6d653b4c2354df65a7f7f2df1925a40a51 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024081927-sustained-humbly-8aaf@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^..

Possible dependencies:

74c2ab6d653b ("smb/client: avoid possible NULL dereference in cifs_free_subrequest()") 519be989717c ("cifs: Add a tracepoint to track credits involved in R/W requests")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 74c2ab6d653b4c2354df65a7f7f2df1925a40a51 Mon Sep 17 00:00:00 2001 From: Su Hui suhui@nfschina.com Date: Thu, 8 Aug 2024 20:23:32 +0800 Subject: [PATCH] smb/client: avoid possible NULL dereference in cifs_free_subrequest()

Clang static checker (scan-build) warning: cifsglob.h:line 890, column 3 Access to field 'ops' results in a dereference of a null pointer.

Commit 519be989717c ("cifs: Add a tracepoint to track credits involved in R/W requests") adds a check for 'rdata->server', and let clang throw this warning about NULL dereference.

When 'rdata->credits.value != 0 && rdata->server == NULL' happens, add_credits_and_wake_if() will call rdata->server->ops->add_credits(). This will cause NULL dereference problem. Add a check for 'rdata->server' to avoid NULL dereference.

Cc: stable@vger.kernel.org Fixes: 69c3c023af25 ("cifs: Implement netfslib hooks") Reviewed-by: David Howells dhowells@redhat.com Signed-off-by: Su Hui suhui@nfschina.com Signed-off-by: Steve French stfrench@microsoft.com

diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c index b2405dd4d4d4..45459af5044d 100644 --- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -315,7 +315,7 @@ static void cifs_free_subrequest(struct netfs_io_subrequest *subreq) #endif }

- if (rdata->credits.value != 0) + if (rdata->credits.value != 0) { trace_smb3_rw_credits(rdata->rreq->debug_id, rdata->subreq.debug_index, rdata->credits.value, @@ -323,8 +323,12 @@ static void cifs_free_subrequest(struct netfs_io_subrequest *subreq) rdata->server ? rdata->server->in_flight : 0, -rdata->credits.value, cifs_trace_rw_credits_free_subreq); + if (rdata->server) + add_credits_and_wake_if(rdata->server, &rdata->credits, 0); + else + rdata->credits.value = 0; + }

- add_credits_and_wake_if(rdata->server, &rdata->credits, 0); if (rdata->have_xid) free_xid(rdata->xid); }