From: YueHaibing <yuehaibing@huawei.com>
To: <socketcan@hartkopp.net>, <mkl@pengutronix.de>,
<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
<pabeni@redhat.com>, <urs.thuermann@volkswagen.de>
Cc: <linux-can@vger.kernel.org>, <netdev@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
YueHaibing <yuehaibing@huawei.com>
Subject: [PATCH] can: bcm: Fix UAF in bcm_proc_show()
Date: Sat, 15 Jul 2023 17:25:43 +0800 [thread overview]
Message-ID: <20230715092543.15548-1-yuehaibing@huawei.com> (raw)
BUG: KASAN: slab-use-after-free in bcm_proc_show+0x969/0xa80
Read of size 8 at addr ffff888155846230 by task cat/7862
CPU: 1 PID: 7862 Comm: cat Not tainted 6.5.0-rc1-00153-gc8746099c197 #230
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xd5/0x150
print_report+0xc1/0x5e0
kasan_report+0xba/0xf0
bcm_proc_show+0x969/0xa80
seq_read_iter+0x4f6/0x1260
seq_read+0x165/0x210
proc_reg_read+0x227/0x300
vfs_read+0x1d5/0x8d0
ksys_read+0x11e/0x240
do_syscall_64+0x35/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Allocated by task 7846:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_kmalloc+0x9e/0xa0
bcm_sendmsg+0x264b/0x44e0
sock_sendmsg+0xda/0x180
____sys_sendmsg+0x735/0x920
___sys_sendmsg+0x11d/0x1b0
__sys_sendmsg+0xfa/0x1d0
do_syscall_64+0x35/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 7846:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x27/0x40
____kasan_slab_free+0x161/0x1c0
slab_free_freelist_hook+0x119/0x220
__kmem_cache_free+0xb4/0x2e0
rcu_core+0x809/0x1bd0
bcm_op is freed before procfs entry be removed in bcm_release(),
this lead to bcm_proc_show() may read the freed bcm_op.
Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
---
net/can/bcm.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 9ba35685b043..9168114fc87f 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -1526,6 +1526,12 @@ static int bcm_release(struct socket *sock)
lock_sock(sk);
+#if IS_ENABLED(CONFIG_PROC_FS)
+ /* remove procfs entry */
+ if (net->can.bcmproc_dir && bo->bcm_proc_read)
+ remove_proc_entry(bo->procname, net->can.bcmproc_dir);
+#endif /* CONFIG_PROC_FS */
+
list_for_each_entry_safe(op, next, &bo->tx_ops, list)
bcm_remove_op(op);
@@ -1561,12 +1567,6 @@ static int bcm_release(struct socket *sock)
list_for_each_entry_safe(op, next, &bo->rx_ops, list)
bcm_remove_op(op);
-#if IS_ENABLED(CONFIG_PROC_FS)
- /* remove procfs entry */
- if (net->can.bcmproc_dir && bo->bcm_proc_read)
- remove_proc_entry(bo->procname, net->can.bcmproc_dir);
-#endif /* CONFIG_PROC_FS */
-
/* remove device reference */
if (bo->bound) {
bo->bound = 0;
--
2.34.1
next reply other threads:[~2023-07-15 9:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-15 9:25 YueHaibing [this message]
2023-07-16 19:31 ` [PATCH] can: bcm: Fix UAF in bcm_proc_show() Oliver Hartkopp
2023-07-17 7:47 ` Marc Kleine-Budde
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230715092543.15548-1-yuehaibing@huawei.com \
--to=yuehaibing@huawei.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kuba@kernel.org \
--cc=linux-can@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mkl@pengutronix.de \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=socketcan@hartkopp.net \
--cc=urs.thuermann@volkswagen.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.