[PATCH 6.6 296/567] libceph: prevent potential out-of-bounds reads in process_message_header()

Greg Kroah-Hartman
2026-03-23T15:06:41Z

6.6-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ilya Dryomov <idryomov@gmail.com>

commit 69fb5d91bba44ecf7eb80530b85fa4fb028921d5 upstream.

If the message frame is (maliciously) corrupted in a way that the
length of the control segment ends up being less than the size of the
message header or a different frame is made to look like a message
frame, out-of-bounds reads may ensue in process_message_header().

Perform an explicit bounds check before decoding the message header.

Cc: stable@vger.kernel.org
Reported-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Markuze <amarkuze@redhat.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ceph/messenger_v2.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

--- a/net/ceph/messenger_v2.c
+++ b/net/ceph/messenger_v2.c
@@ -2868,12 +2868,15 @@ static int process_message_header(struct
void *p, void *end)
{
struct ceph_frame_desc *desc = &con->v2.in_desc;
- struct ceph_msg_header2 *hdr2 = p;
+ struct ceph_msg_header2 *hdr2;
struct ceph_msg_header hdr;
int skip;
int ret;
u64 seq;

+ ceph_decode_need(&p, end, sizeof(*hdr2), bad);
+ hdr2 = p;
+
/* verify seq# */
seq = le64_to_cpu(hdr2->seq);
if ((s64)seq - (s64)con->in_seq < 1) {
@@ -2904,6 +2907,10 @@ static int process_message_header(struct
WARN_ON(!con->in_msg);
WARN_ON(con->in_msg->con != con);
return 1;
+
+bad:
+ pr_err("failed to decode message header\n");
+ return -EINVAL;
}

static int process_message(struct ceph_connection *con)