[PATCH] cifs: Fix oops due to uninitialised variable

From: David Howells
Date: Tue Aug 19 2025 - 11:28:02 EST


Fix smb3_init_transform_rq() to initialise buffer to NULL before calling
netfs_alloc_folioq_buffer() as netfs assumes it can append to the buffer it
is given. Setting it to NULL means it should start a fresh buffer, but the
value is currently undefined.

Fixes: a2906d3316fc ("cifs: Switch crypto buffer to use a folio_queue rather than an xarray")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Steve French <sfrench@xxxxxxxxx>
cc: Paulo Alcantara <pc@xxxxxxxxxxxxx>
cc: linux-cifs@xxxxxxxxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
---
fs/smb/client/smb2ops.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index ad8947434b71..cd0c9b5a35c3 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -4487,7 +4487,7 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, int num_rqst,
for (int i = 1; i < num_rqst; i++) {
struct smb_rqst *old = &old_rq[i - 1];
struct smb_rqst *new = &new_rq[i];
- struct folio_queue *buffer;
+ struct folio_queue *buffer = NULL;
size_t size = iov_iter_count(&old->rq_iter);

orig_len += smb_rqst_len(server, old);