6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Su Hui <suhui@xxxxxxxxxxxx>
[ Upstream commit 74c2ab6d653b4c2354df65a7f7f2df1925a40a51 ]
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@xxxxxxxxxxxxxxx
Fixes: 69c3c023af25 ("cifs: Implement netfslib hooks")
Reviewed-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/smb/client/file.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index b413cfef05422..1fc66bcf49eb4 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -316,7 +316,7 @@ 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,
@@ -324,8 +324,12 @@ 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);
}
--
2.43.0
