From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
syzbot+c82752228ed975b0a623@syzkaller.appspotmail.com,
Peilin Ye <yepeilin.cs@gmail.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.14 01/14] AX.25: Fix out-of-bounds read in ax25_connect()
Date: Thu, 30 Jul 2020 10:04:44 +0200 [thread overview]
Message-ID: <20200730074418.959770368@linuxfoundation.org> (raw)
In-Reply-To: <20200730074418.882736401@linuxfoundation.org>
From: Peilin Ye <yepeilin.cs@gmail.com>
[ Upstream commit 2f2a7ffad5c6cbf3d438e813cfdc88230e185ba6 ]
Checks on `addr_len` and `fsa->fsa_ax25.sax25_ndigis` are insufficient.
ax25_connect() can go out of bounds when `fsa->fsa_ax25.sax25_ndigis`
equals to 7 or 8. Fix it.
This issue has been reported as a KMSAN uninit-value bug, because in such
a case, ax25_connect() reaches into the uninitialized portion of the
`struct sockaddr_storage` statically allocated in __sys_connect().
It is safe to remove `fsa->fsa_ax25.sax25_ndigis > AX25_MAX_DIGIS` because
`addr_len` is guaranteed to be less than or equal to
`sizeof(struct full_sockaddr_ax25)`.
Reported-by: syzbot+c82752228ed975b0a623@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=55ef9d629f3b3d7d70b69558015b63b48d01af66
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ax25/af_ax25.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1191,7 +1191,9 @@ static int __must_check ax25_connect(str
if (addr_len > sizeof(struct sockaddr_ax25) &&
fsa->fsa_ax25.sax25_ndigis != 0) {
/* Valid number of digipeaters ? */
- if (fsa->fsa_ax25.sax25_ndigis < 1 || fsa->fsa_ax25.sax25_ndigis > AX25_MAX_DIGIS) {
+ if (fsa->fsa_ax25.sax25_ndigis < 1 ||
+ addr_len < sizeof(struct sockaddr_ax25) +
+ sizeof(ax25_address) * fsa->fsa_ax25.sax25_ndigis) {
err = -EINVAL;
goto out_release;
}
next prev parent reply other threads:[~2020-07-30 8:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-30 8:04 [PATCH 4.14 00/14] 4.14.191-rc1 review Greg Kroah-Hartman
2020-07-30 8:04 ` Greg Kroah-Hartman [this message]
2020-07-30 8:04 ` [PATCH 4.14 02/14] AX.25: Prevent out-of-bounds read in ax25_sendmsg() Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 03/14] dev: Defer free of skbs in flush_backlog Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 04/14] drivers/net/wan/x25_asy: Fix to make it work Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 05/14] net-sysfs: add a newline when printing tx_timeout by sysfs Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 06/14] net: udp: Fix wrong clean up for IS_UDPLITE macro Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 07/14] rxrpc: Fix sendmsg() returning EPIPE due to recvmsg() returning ENODATA Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 08/14] AX.25: Prevent integer overflows in connect and sendmsg Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 09/14] ip6_gre: fix null-ptr-deref in ip6gre_init_net() Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 10/14] rtnetlink: Fix memory(net_device) leak when ->newlink fails Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 11/14] tcp: allow at most one TLP probe per flight Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 12/14] mm/page_owner.c: remove drain_all_pages from init_early_allocated_pages Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 13/14] regmap: debugfs: check count when read regmap file Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 14/14] xfs: set format back to extents if xfs_bmap_extents_to_btree Greg Kroah-Hartman
2020-07-30 16:47 ` [PATCH 4.14 00/14] 4.14.191-rc1 review Guenter Roeck
2020-07-31 12:15 ` Naresh Kamboju
2020-07-31 12:42 ` Jon Hunter
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