net: rose: fix invalid array index in rose_kill_by_device()

[ Upstream commit 6595beb40fb0ec47223d3f6058ee40354694c8e4 ]

rose_kill_by_device() collects sockets into a local array[] and then
iterates over them to disconnect sockets bound to a device being brought
down.

The loop mistakenly indexes array[cnt] instead of array[i]. For cnt <
ARRAY_SIZE(array), this reads an uninitialized entry; for cnt ==
ARRAY_SIZE(array), it is an out-of-bounds read. Either case can lead to
an invalid socket pointer dereference and also leaks references taken
via sock_hold().

Fix the index to use i.

Fixes: 64b8bc7d5f143 ("net/rose: fix races in rose_kill_by_device()")
Co-developed-by: Fatma Alwasmi <falwasmi@purdue.edu>
Signed-off-by: Fatma Alwasmi <falwasmi@purdue.edu>
Signed-off-by: Pwnverse <stanksal@purdue.edu>
Link: https://patch.msgid.link/20251222212227.4116041-1-ritviktanksalkar@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index b8078b42f5de6738303ff6f6e0e57f1b06fb53be..1676c9f4ab848b783c9468f39ac30a8cc9d0efdf 100644 (file)
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -205,7 +205,7 @@ start:
        spin_unlock_bh(&rose_list_lock);
 
        for (i = 0; i < cnt; i++) {
-               sk = array[cnt];
+               sk = array[i];
                rose = rose_sk(sk);
                lock_sock(sk);
                spin_lock_bh(&rose_list_lock);