commit 110d0fa2d4d1f754242f6775baec43776a9adb35
author Anastasia Belova <nabelova31@gmail.com> Mon Jun 02 11:57:17 2025 +0300
committer Jason Wang <jasowang@redhat.com> Mon Jul 14 10:13:37 2025 +0800
tree aeb4be33276d593a69f716f10c9a75c9876adb51
parent 9a4e273ddec3927920c5958d2226c6b38b543336

net: fix buffer overflow in af_xdp_umem_create()

s->pool has n_descs elements so maximum i should be
n_descs - 1. Fix the upper bound.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: cb039ef3d9 ("net: add initial support for AF_XDP network backend")
Cc: qemu-stable@nongnu.org
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Anastasia Belova <nabelova31@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/af-xdp.c

diff --git a/net/af-xdp.c b/net/af-xdp.c
index 01c5fb9..d022534 100644
--- a/net/af-xdp.c
+++ b/net/af-xdp.c
@@ -323,7 +323,7 @@
 
     s->pool = g_new(uint64_t, n_descs);
     /* Fill the pool in the opposite order, because it's a LIFO queue. */
-    for (i = n_descs; i >= 0; i--) {
+    for (i = n_descs - 1; i >= 0; i--) {
         s->pool[i] = i * XSK_UMEM__DEFAULT_FRAME_SIZE;
     }
     s->n_pool = n_descs;