From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Eric Biggers <ebiggers@google.com>,
syzbot+6bf095f9becf5efef645@syzkaller.appspotmail.com,
syzbot+31c16aa4202dace3812e@syzkaller.appspotmail.com,
Jakub Kicinski <jakub.kicinski@netronome.com>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 08/33] llc: fix sk_buff leak in llc_sap_state_process()
Date: Sat, 26 Oct 2019 09:20:45 -0400 [thread overview]
Message-ID: <20191026132110.4026-8-sashal@kernel.org> (raw)
In-Reply-To: <20191026132110.4026-1-sashal@kernel.org>
From: Eric Biggers <ebiggers@google.com>
[ Upstream commit c6ee11c39fcc1fb55130748990a8f199e76263b4 ]
syzbot reported:
BUG: memory leak
unreferenced object 0xffff888116270800 (size 224):
comm "syz-executor641", pid 7047, jiffies 4294947360 (age 13.860s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 20 e1 2a 81 88 ff ff 00 40 3d 2a 81 88 ff ff . .*.....@=*....
backtrace:
[<000000004d41b4cc>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<000000004d41b4cc>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<000000004d41b4cc>] slab_alloc_node mm/slab.c:3269 [inline]
[<000000004d41b4cc>] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579
[<00000000506a5965>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198
[<000000001ba5a161>] alloc_skb include/linux/skbuff.h:1058 [inline]
[<000000001ba5a161>] alloc_skb_with_frags+0x5f/0x250 net/core/skbuff.c:5327
[<0000000047d9c78b>] sock_alloc_send_pskb+0x269/0x2a0 net/core/sock.c:2225
[<000000003828fe54>] sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2242
[<00000000e34d94f9>] llc_ui_sendmsg+0x10a/0x540 net/llc/af_llc.c:933
[<00000000de2de3fb>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000de2de3fb>] sock_sendmsg+0x54/0x70 net/socket.c:671
[<000000008fe16e7a>] __sys_sendto+0x148/0x1f0 net/socket.c:1964
[...]
The bug is that llc_sap_state_process() always takes an extra reference
to the skb, but sometimes neither llc_sap_next_state() nor
llc_sap_state_process() itself drops this reference.
Fix it by changing llc_sap_next_state() to never consume a reference to
the skb, rather than sometimes do so and sometimes not. Then remove the
extra skb_get() and kfree_skb() from llc_sap_state_process().
Reported-by: syzbot+6bf095f9becf5efef645@syzkaller.appspotmail.com
Reported-by: syzbot+31c16aa4202dace3812e@syzkaller.appspotmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/llc/llc_s_ac.c | 12 +++++++++---
net/llc/llc_sap.c | 23 ++++++++---------------
2 files changed, 17 insertions(+), 18 deletions(-)
diff --git a/net/llc/llc_s_ac.c b/net/llc/llc_s_ac.c
index a94bd56bcac6f..7ae4cc684d3ab 100644
--- a/net/llc/llc_s_ac.c
+++ b/net/llc/llc_s_ac.c
@@ -58,8 +58,10 @@ int llc_sap_action_send_ui(struct llc_sap *sap, struct sk_buff *skb)
ev->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_ui_cmd(skb);
rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
- if (likely(!rc))
+ if (likely(!rc)) {
+ skb_get(skb);
rc = dev_queue_xmit(skb);
+ }
return rc;
}
@@ -81,8 +83,10 @@ int llc_sap_action_send_xid_c(struct llc_sap *sap, struct sk_buff *skb)
ev->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_xid_cmd(skb, LLC_XID_NULL_CLASS_2, 0);
rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
- if (likely(!rc))
+ if (likely(!rc)) {
+ skb_get(skb);
rc = dev_queue_xmit(skb);
+ }
return rc;
}
@@ -135,8 +139,10 @@ int llc_sap_action_send_test_c(struct llc_sap *sap, struct sk_buff *skb)
ev->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_test_cmd(skb);
rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
- if (likely(!rc))
+ if (likely(!rc)) {
+ skb_get(skb);
rc = dev_queue_xmit(skb);
+ }
return rc;
}
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index d90928f502260..a7534950e60a1 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -197,29 +197,22 @@ static int llc_sap_next_state(struct llc_sap *sap, struct sk_buff *skb)
* After executing actions of the event, upper layer will be indicated
* if needed(on receiving an UI frame). sk can be null for the
* datalink_proto case.
+ *
+ * This function always consumes a reference to the skb.
*/
static void llc_sap_state_process(struct llc_sap *sap, struct sk_buff *skb)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
- /*
- * We have to hold the skb, because llc_sap_next_state
- * will kfree it in the sending path and we need to
- * look at the skb->cb, where we encode llc_sap_state_ev.
- */
- skb_get(skb);
ev->ind_cfm_flag = 0;
llc_sap_next_state(sap, skb);
- if (ev->ind_cfm_flag == LLC_IND) {
- if (skb->sk->sk_state == TCP_LISTEN)
- kfree_skb(skb);
- else {
- llc_save_primitive(skb->sk, skb, ev->prim);
- /* queue skb to the user. */
- if (sock_queue_rcv_skb(skb->sk, skb))
- kfree_skb(skb);
- }
+ if (ev->ind_cfm_flag == LLC_IND && skb->sk->sk_state != TCP_LISTEN) {
+ llc_save_primitive(skb->sk, skb, ev->prim);
+
+ /* queue skb to the user. */
+ if (sock_queue_rcv_skb(skb->sk, skb) == 0)
+ return;
}
kfree_skb(skb);
}
--
2.20.1
next prev parent reply other threads:[~2019-10-26 13:21 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-26 13:20 [PATCH AUTOSEL 4.14 01/33] iommu/arm-smmu: Free context bitmap in the err path of arm_smmu_init_domain_context Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 02/33] mac80211_hwsim: fix incorrect dev_alloc_name failure goto Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 03/33] nvme: retain split access workaround for capability reads Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 04/33] net: dsa: b53: Do not clear existing mirrored port mask Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 05/33] net: stmmac: gmac4+: Not all Unicast addresses may be available Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 06/33] rxrpc: Fix call ref leak Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 07/33] mac80211: accept deauth frames in IBSS mode Sasha Levin
2019-10-26 13:20 ` Sasha Levin [this message]
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 09/33] llc: fix sk_buff leak in llc_conn_service() Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 10/33] llc: fix another potential sk_buff leak in llc_ui_sendmsg() Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 11/33] llc: fix sk_buff refcounting in llc_conn_state_process() Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 12/33] NFC: pn533: fix use-after-free and memleaks Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 13/33] iwlwifi: dbg_ini: fix memory leak in alloc_sgtable Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 14/33] net: stmmac: fix length of PTP clock's name string Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 15/33] bonding: fix potential NULL deref in bond_update_slave_arr Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 16/33] act_mirred: Fix mirred_init_module error handling Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 17/33] net: usb: qmi_wwan: add Telit 0x1050 composition Sasha Levin
2020-09-07 9:36 ` Kristian Evensen
2020-09-07 18:15 ` Sasha Levin
2020-09-08 0:33 ` Lars Melin
2020-09-08 12:12 ` Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 18/33] net: avoid possible false sharing in sk_leave_memory_pressure() Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 19/33] net: add {READ|WRITE}_ONCE() annotations on ->rskq_accept_head Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 20/33] drm/msm/dsi: Implement reset correctly Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 21/33] hrtimer: Annotate lockless access to timer->base Sasha Levin
2019-10-26 13:20 ` [PATCH AUTOSEL 4.14 22/33] xtensa: fix {get,put}_user() for 64bit values Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 23/33] net: i82596: fix dma_alloc_attr for sni_82596 Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 24/33] net: bcmgenet: Fix RGMII_MODE_EN value for GENET v1/2/3 Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 25/33] net: usb: sr9800: fix uninitialized local variable Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 26/33] md/raid0: fix warning message for parameter default_layout Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 27/33] net: stmmac: disable/enable ptp_ref_clk in suspend/resume flow Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 28/33] usb: hso: obey DMA rules in tiocmget Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 29/33] x86/hyperv: Set pv_info.name to "Hyper-V" Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 30/33] net: usb: lan78xx: Connect PHY before registering MAC Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 31/33] scripts/gdb: fix lx-dmesg when CONFIG_PRINTK_CALLER is set Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 32/33] ocfs2: fix error handling in ocfs2_setattr() Sasha Levin
2019-10-26 13:21 ` [PATCH AUTOSEL 4.14 33/33] scripts/gdb: fix debugging modules on s390 Sasha Levin
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