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+7010af67ced6105e5ab6@syzkaller.appspotmail.com,
Vasily Averin <vvs@virtuozzo.com>,
Willem de Bruijn <willemb@google.com>,
Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 4.14 28/28] net: drop bogus skb with CHECKSUM_PARTIAL and offset beyond end of trimmed packet
Date: Fri, 15 Jan 2021 13:28:05 +0100 [thread overview]
Message-ID: <20210115121958.158487270@linuxfoundation.org> (raw)
In-Reply-To: <20210115121956.731354372@linuxfoundation.org>
From: Vasily Averin <vvs@virtuozzo.com>
commit 54970a2fbb673f090b7f02d7f57b10b2e0707155 upstream.
syzbot reproduces BUG_ON in skb_checksum_help():
tun creates (bogus) skb with huge partial-checksummed area and
small ip packet inside. Then ip_rcv trims the skb based on size
of internal ip packet, after that csum offset points beyond of
trimmed skb. Then checksum_tg() called via netfilter hook
triggers BUG_ON:
offset = skb_checksum_start_offset(skb);
BUG_ON(offset >= skb_headlen(skb));
To work around the problem this patch forces pskb_trim_rcsum_slow()
to return -EINVAL in described scenario. It allows its callers to
drop such kind of packets.
Link: https://syzkaller.appspot.com/bug?id=b419a5ca95062664fe1a60b764621eb4526e2cd0
Reported-by: syzbot+7010af67ced6105e5ab6@syzkaller.appspotmail.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/1b2494af-2c56-8ee2-7bc0-923fcad1cdf8@virtuozzo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/core/skbuff.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1850,6 +1850,12 @@ int pskb_trim_rcsum_slow(struct sk_buff
skb->csum = csum_block_sub(skb->csum,
skb_checksum(skb, len, delta, 0),
len);
+ } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ int hdlen = (len > skb_headlen(skb)) ? skb_headlen(skb) : len;
+ int offset = skb_checksum_start_offset(skb) + skb->csum_offset;
+
+ if (offset + sizeof(__sum16) > hdlen)
+ return -EINVAL;
}
return __pskb_trim(skb, len);
}
next prev parent reply other threads:[~2021-01-15 12:32 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-15 12:27 [PATCH 4.14 00/28] 4.14.216-rc1 review Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 01/28] powerpc: Fix incorrect stw{, ux, u, x} instructions in __set_pte_at Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 02/28] net: cdc_ncm: correct overhead in delayed_ndp_size Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 03/28] net: vlan: avoid leaks on register_vlan_dev() failures Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 04/28] net: ip: always refragment ip defragmented packets Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 05/28] net: fix pmtu check in nopmtudisc mode Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 06/28] x86/resctrl: Use an IPI instead of task_work_add() to update PQR_ASSOC MSR Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 07/28] x86/resctrl: Dont move a task to the same resource group Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 08/28] vmlinux.lds.h: Add PGO and AutoFDO input sections Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 09/28] drm/i915: Fix mismatch between misplaced vma check and vma insert Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 10/28] ubifs: wbuf: Dont leak kernel memory to flash Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 11/28] spi: pxa2xx: Fix use-after-free on unbind Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 12/28] iio: imu: st_lsm6dsx: flip irq return logic Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 13/28] iio: imu: st_lsm6dsx: fix edge-trigger interrupts Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 14/28] ARM: OMAP2+: omap_device: fix idling of devices during probe Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 15/28] i2c: sprd: use a specific timeout to avoid system hang up issue Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 16/28] cpufreq: powernow-k8: pass policy rather than use cpufreq_cpu_get() Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 17/28] spi: stm32: FIFO threshold level - fix align packet size Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 18/28] dmaengine: xilinx_dma: check dma_async_device_register return value Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 19/28] dmaengine: xilinx_dma: fix mixed_enum_type coverity warning Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 20/28] wil6210: select CONFIG_CRC32 Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 21/28] block: rsxx: " Greg Kroah-Hartman
2021-01-15 12:27 ` [PATCH 4.14 22/28] iommu/intel: Fix memleak in intel_irq_remapping_alloc Greg Kroah-Hartman
2021-01-15 12:28 ` [PATCH 4.14 23/28] net/mlx5e: Fix memleak in mlx5e_create_l2_table_groups Greg Kroah-Hartman
2021-01-15 12:28 ` [PATCH 4.14 24/28] net/mlx5e: Fix two double free cases Greg Kroah-Hartman
2021-01-15 12:28 ` [PATCH 4.14 25/28] wan: ds26522: select CONFIG_BITREVERSE Greg Kroah-Hartman
2021-01-15 12:28 ` [PATCH 4.14 26/28] KVM: arm64: Dont access PMCR_EL0 when no PMU is available Greg Kroah-Hartman
2021-01-15 12:28 ` [PATCH 4.14 27/28] block: fix use-after-free in disk_part_iter_next Greg Kroah-Hartman
2021-01-15 12:28 ` Greg Kroah-Hartman [this message]
2021-01-15 21:17 ` [PATCH 4.14 00/28] 4.14.216-rc1 review Guenter Roeck
2021-01-16 6:38 ` Naresh Kamboju
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