From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Jacob Wen <jian.w.wen@oracle.com>,
Guillaume Nault <gnault@redhat.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.14 18/46] l2tp: fix reading optional fields of L2TPv3
Date: Mon, 4 Feb 2019 11:36:49 +0100 [thread overview]
Message-ID: <20190204103611.998065860@linuxfoundation.org> (raw)
In-Reply-To: <20190204103608.651205056@linuxfoundation.org>
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jacob Wen <jian.w.wen@oracle.com>
[ Upstream commit 4522a70db7aa5e77526a4079628578599821b193 ]
Use pskb_may_pull() to make sure the optional fields are in skb linear
parts, so we can safely read them later.
It's easy to reproduce the issue with a net driver that supports paged
skb data. Just create a L2TPv3 over IP tunnel and then generates some
network traffic.
Once reproduced, rx err in /sys/kernel/debug/l2tp/tunnels will increase.
Changes in v4:
1. s/l2tp_v3_pull_opt/l2tp_v3_ensure_opt_in_linear/
2. s/tunnel->version != L2TP_HDR_VER_2/tunnel->version == L2TP_HDR_VER_3/
3. Add 'Fixes' in commit messages.
Changes in v3:
1. To keep consistency, move the code out of l2tp_recv_common.
2. Use "net" instead of "net-next", since this is a bug fix.
Changes in v2:
1. Only fix L2TPv3 to make code simple.
To fix both L2TPv3 and L2TPv2, we'd better refactor l2tp_recv_common.
It's complicated to do so.
2. Reloading pointers after pskb_may_pull
Fixes: f7faffa3ff8e ("l2tp: Add L2TPv3 protocol support")
Fixes: 0d76751fad77 ("l2tp: Add L2TPv3 IP encapsulation (no UDP) support")
Fixes: a32e0eec7042 ("l2tp: introduce L2TPv3 IP encapsulation support for IPv6")
Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/l2tp/l2tp_core.c | 4 ++++
net/l2tp/l2tp_core.h | 20 ++++++++++++++++++++
net/l2tp/l2tp_ip.c | 3 +++
net/l2tp/l2tp_ip6.c | 3 +++
4 files changed, 30 insertions(+)
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -983,6 +983,10 @@ static int l2tp_udp_recv_core(struct l2t
goto error;
}
+ if (tunnel->version == L2TP_HDR_VER_3 &&
+ l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
+ goto error;
+
l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook);
l2tp_session_dec_refcount(session);
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -331,6 +331,26 @@ static inline int l2tp_get_l2specific_le
}
}
+static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb,
+ unsigned char **ptr, unsigned char **optr)
+{
+ int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
+
+ if (opt_len > 0) {
+ int off = *ptr - *optr;
+
+ if (!pskb_may_pull(skb, off + opt_len))
+ return -1;
+
+ if (skb->data != *optr) {
+ *optr = skb->data;
+ *ptr = skb->data + off;
+ }
+ }
+
+ return 0;
+}
+
#define l2tp_printk(ptr, type, func, fmt, ...) \
do { \
if (((ptr)->debug) & (type)) \
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -165,6 +165,9 @@ static int l2tp_ip_recv(struct sk_buff *
print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
}
+ if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
+ goto discard_sess;
+
l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);
l2tp_session_dec_refcount(session);
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -178,6 +178,9 @@ static int l2tp_ip6_recv(struct sk_buff
print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
}
+ if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
+ goto discard_sess;
+
l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
tunnel->recv_payload_hook);
l2tp_session_dec_refcount(session);
next prev parent reply other threads:[~2019-02-04 10:44 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-04 10:36 [PATCH 4.14 00/46] 4.14.98-stable review Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 01/46] Fix "net: ipv4: do not handle duplicate fragments as overlapping" Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 02/46] ipv6: Consider sk_bound_dev_if when binding a socket to an address Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 03/46] ipv6: sr: clear IP6CB(skb) on SRH ip4ip6 encapsulation Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 04/46] l2tp: copy 4 more bytes to linear part if necessary Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 05/46] net/mlx4_core: Add masking for a few queries on HCA caps Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 06/46] netrom: switch to sock timer API Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 07/46] net/rose: fix NULL ax25_cb kernel panic Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 08/46] net: set default network namespace in init_dummy_netdev() Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 09/46] ucc_geth: Reset BQL queue when stopping device Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 10/46] net/mlx5e: Allow MAC invalidation while spoofchk is ON Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 11/46] Revert "net/mlx5e: E-Switch, Initialize eswitch only if eswitch manager" Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 12/46] virtio_net: Dont enable NAPI when interface is down Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 13/46] virtio_net: Dont call free_old_xmit_skbs for xdp_frames Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 14/46] virtio_net: Fix not restoring real_num_rx_queues Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 15/46] sctp: improve the events for sctp stream adding Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 16/46] sctp: improve the events for sctp stream reset Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 17/46] l2tp: remove l2specific_len dependency in l2tp_core Greg Kroah-Hartman
2019-02-04 10:36 ` Greg Kroah-Hartman [this message]
2019-02-04 10:36 ` [PATCH 4.14 19/46] ipvlan, l3mdev: fix broken l3s mode wrt local routes Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 20/46] CIFS: Do not count -ENODATA as failure for query directory Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 21/46] fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb() Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 22/46] iommu/vt-d: Fix memory leak in intel_iommu_put_resv_regions() Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 23/46] selftests/seccomp: Enhance per-arch ptrace syscall skip tests Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 24/46] NFS: Fix up return value on fatal errors in nfs_page_async_flush() Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 25/46] ARM: cns3xxx: Fix writing to wrong PCI config registers after alignment Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 26/46] arm64: kaslr: ensure randomized quantities are clean also when kaslr is off Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 27/46] arm64: hyp-stub: Forbid kprobing of the hyp-stub Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.14 28/46] arm64: hibernate: Clean the __hyp_text to PoC after resume Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 29/46] gpio: altera-a10sr: Set proper output level for direction_output Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 30/46] gpio: pcf857x: Fix interrupts on multiple instances Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 31/46] gfs2: Revert "Fix loop in gfs2_rbm_find" Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 32/46] mmc: bcm2835: Fix DMA channel leak on probe error Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 33/46] ALSA: hda/realtek - Fixed hp_pin no value Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 34/46] IB/hfi1: Remove overly conservative VM_EXEC flag check Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 35/46] platform/x86: asus-nb-wmi: Map 0x35 to KEY_SCREENLOCK Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 36/46] platform/x86: asus-nb-wmi: Drop mapping of 0x33 and 0x34 scan codes Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 37/46] mmc: sdhci-iproc: handle mmc_of_parse() errors during probe Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 38/46] kernel/exit.c: release ptraced tasks before zap_pid_ns_processes Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 39/46] oom, oom_reaper: do not enqueue same task twice Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 40/46] mm, oom: fix use-after-free in oom_kill_process Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 41/46] mm: hwpoison: use do_send_sig_info() instead of force_sig() Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 42/46] mm: migrate: dont rely on __PageMovable() of newpage after unlocking it Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 43/46] md/raid5: fix out of memory during raid cache recovery Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 44/46] cifs: Always resolve hostname before reconnecting Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 45/46] drivers: core: Remove glue dirs from sysfs earlier Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.14 46/46] fanotify: fix handling of events on child sub-directory Greg Kroah-Hartman
2019-02-04 21:49 ` [PATCH 4.14 00/46] 4.14.98-stable review Guenter Roeck
2019-02-05 6:38 ` Naresh Kamboju
2019-02-05 10:20 ` Jon Hunter
2019-02-05 14:42 ` Greg Kroah-Hartman
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