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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>,
	Jakub Kicinski <jakub.kicinski@netronome.com>,
	Sasha Levin <sashal@kernel.org>,
	netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.2 62/63] sch_netem: fix a divide by zero in tabledist()
Date: Tue,  1 Oct 2019 12:41:24 -0400	[thread overview]
Message-ID: <20191001164125.15398-62-sashal@kernel.org> (raw)
In-Reply-To: <20191001164125.15398-1-sashal@kernel.org>

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit b41d936b5ecfdb3a4abc525ce6402a6c49cffddc ]

syzbot managed to crash the kernel in tabledist() loading
an empty distribution table.

	t = dist->table[rnd % dist->size];

Simply return an error when such load is attempted.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/sched/sch_netem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index b17f2ed970e29..f5cb35e550f8d 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -777,7 +777,7 @@ static int get_dist_table(struct Qdisc *sch, struct disttable **tbl,
 	struct disttable *d;
 	int i;
 
-	if (n > NETEM_DIST_MAX)
+	if (!n || n > NETEM_DIST_MAX)
 		return -EINVAL;
 
 	d = kvmalloc(sizeof(struct disttable) + n * sizeof(s16), GFP_KERNEL);
-- 
2.20.1


      parent reply	other threads:[~2019-10-01 16:54 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20191001164125.15398-1-sashal@kernel.org>
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 05/63] xprtrdma: Send Queue size grows after a reconnect Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 06/63] 9p: Transport error uninitialized Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 15/63] SUNRPC: RPC level errors should always set task->tk_rpc_status Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 17/63] netfilter: nf_tables: allow lookups in dynamic sets Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 21/63] SUNRPC: Don't try to parse incomplete RPC messages Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 22/63] net/sched: act_sample: don't push mac header on ip6gre ingress Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 24/63] cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 25/63] usbnet: ignore endpoints with " Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 26/63] net/phy: fix DP83865 10 Mbps HDX loopback disable function Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 27/63] net_sched: add max len check for TCA_KIND Sasha Levin
2019-10-01 16:40 ` [PATCH AUTOSEL 5.2 34/63] net/mlx5e: Fix traffic duplication in ethtool steering Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 38/63] arcnet: provide a buffer big enough to actually receive packets Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 40/63] ppp: Fix memory leak in ppp_write Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 49/63] bpf: Fix bpf_event_output re-entry issue Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 50/63] macsec: drop skb sk before calling gro_cells_receive Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 53/63] nfp: flower: fix memory leak in nfp_flower_spawn_vnic_reprs Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 54/63] net: phy: micrel: add Asym Pause workaround for KSZ9021 Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 55/63] mlxsw: spectrum_flower: Fail in case user specifies multiple mirror actions Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 56/63] vrf: Do not attempt to create IPv6 mcast rule if IPv6 is disabled Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 57/63] nfp: flower: prevent memory leak in nfp_flower_spawn_phy_reprs Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 58/63] nfp: abm: fix memory leak in nfp_abm_u32_knode_replace Sasha Levin
2019-10-01 16:41 ` [PATCH AUTOSEL 5.2 61/63] usbnet: sanity checking of packet sizes and device mtu Sasha Levin
2019-10-01 16:41 ` Sasha Levin [this message]

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