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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>,
	syzbot <syzkaller@googlegroups.com>,
	Mahesh Bandewar <maheshb@google.com>,
	Jakub Kicinski <jakub.kicinski@netronome.com>,
	Sasha Levin <sashal@kernel.org>,
	netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.3 10/33] bonding: fix potential NULL deref in bond_update_slave_arr
Date: Fri, 25 Oct 2019 09:54:42 -0400	[thread overview]
Message-ID: <20191025135505.24762-10-sashal@kernel.org> (raw)
In-Reply-To: <20191025135505.24762-1-sashal@kernel.org>

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit a7137534b597b7c303203e6bc3ed87e87a273bb8 ]

syzbot got a NULL dereference in bond_update_slave_arr() [1],
happening after a failure to allocate bond->slave_arr

A workqueue (bond_slave_arr_handler) is supposed to retry
the allocation later, but if the slave is removed before
the workqueue had a chance to complete, bond->slave_arr
can still be NULL.

[1]

Failed to build slave-array.
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN PTI
Modules linked in:
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:bond_update_slave_arr.cold+0xc6/0x198 drivers/net/bonding/bond_main.c:4039
RSP: 0018:ffff88018fe33678 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc9000290b000
RDX: 0000000000000000 RSI: ffffffff82b63037 RDI: ffff88019745ea20
RBP: ffff88018fe33760 R08: ffff880170754280 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88019745ea00 R14: 0000000000000000 R15: ffff88018fe338b0
FS:  00007febd837d700(0000) GS:ffff8801dad00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004540a0 CR3: 00000001c242e005 CR4: 00000000001626f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 [<ffffffff82b5b45e>] __bond_release_one+0x43e/0x500 drivers/net/bonding/bond_main.c:1923
 [<ffffffff82b5b966>] bond_release drivers/net/bonding/bond_main.c:2039 [inline]
 [<ffffffff82b5b966>] bond_do_ioctl+0x416/0x870 drivers/net/bonding/bond_main.c:3562
 [<ffffffff83ae25f4>] dev_ifsioc+0x6f4/0x940 net/core/dev_ioctl.c:328
 [<ffffffff83ae2e58>] dev_ioctl+0x1b8/0xc70 net/core/dev_ioctl.c:495
 [<ffffffff83995ffd>] sock_do_ioctl+0x1bd/0x300 net/socket.c:1088
 [<ffffffff83996a80>] sock_ioctl+0x300/0x5d0 net/socket.c:1196
 [<ffffffff81b124db>] vfs_ioctl fs/ioctl.c:47 [inline]
 [<ffffffff81b124db>] file_ioctl fs/ioctl.c:501 [inline]
 [<ffffffff81b124db>] do_vfs_ioctl+0xacb/0x1300 fs/ioctl.c:688
 [<ffffffff81b12dc6>] SYSC_ioctl fs/ioctl.c:705 [inline]
 [<ffffffff81b12dc6>] SyS_ioctl+0xb6/0xe0 fs/ioctl.c:696
 [<ffffffff8101ccc8>] do_syscall_64+0x528/0x770 arch/x86/entry/common.c:305
 [<ffffffff84400091>] entry_SYSCALL_64_after_hwframe+0x42/0xb7

Fixes: ee6377147409 ("bonding: Simplify the xmit function for modes that use xmit_hash")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/bonding/bond_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 931d9d9356869..21d8fcc83c9ce 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4039,7 +4039,7 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave)
 		 * this to-be-skipped slave to send a packet out.
 		 */
 		old_arr = rtnl_dereference(bond->slave_arr);
-		for (idx = 0; idx < old_arr->count; idx++) {
+		for (idx = 0; old_arr != NULL && idx < old_arr->count; idx++) {
 			if (skipslave == old_arr->arr[idx]) {
 				old_arr->arr[idx] =
 				    old_arr->arr[old_arr->count-1];
-- 
2.20.1


  parent reply	other threads:[~2019-10-25 14:07 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-25 13:54 [PATCH AUTOSEL 5.3 01/33] net: ipv6: fix listify ip6_rcv_finish in case of forwarding Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 02/33] sch_netem: fix rcu splat in netem_enqueue() Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 03/33] net: sched: sch_sfb: don't call qdisc_put() while holding tree lock Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 04/33] rxrpc: Fix call ref leak Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 05/33] rxrpc: Fix trace-after-put looking at the put peer record Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 06/33] rxrpc: rxrpc_peer needs to hold a ref on the rxrpc_local record Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 07/33] llc: fix sk_buff leak in llc_sap_state_process() Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 08/33] llc: fix sk_buff leak in llc_conn_service() Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 09/33] NFC: pn533: fix use-after-free and memleaks Sasha Levin
2019-10-25 13:54 ` Sasha Levin [this message]
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 11/33] netfilter: conntrack: avoid possible false sharing Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 12/33] blackhole_netdev: fix syzkaller reported issue Sasha Levin
2019-10-25 15:49   ` Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 13/33] net: usb: sr9800: fix uninitialized local variable Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 16/33] netfilter: connlabels: prefer static lock initialiser Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 19/33] net/rds: Whitelist rdma_cookie and rx_tstamp for usercopy Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 21/33] ath9k: dynack: fix possible deadlock in ath_dynack_node_{de}init Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 25/33] net: sched: sch_htb: don't call qdisc_put() while holding tree lock Sasha Levin
2019-10-25 13:54 ` [PATCH AUTOSEL 5.3 26/33] net: sched: multiq: " Sasha Levin
2019-10-25 13:55 ` [PATCH AUTOSEL 5.3 29/33] ipv6: Handle race in addrconf_dad_work Sasha Levin
2019-10-25 13:55 ` [PATCH AUTOSEL 5.3 31/33] sctp: add chunks to sk_backlog when the newsk sk_socket is not set Sasha Levin

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