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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Pavel Skripkin <paskripkin@gmail.com>,
	syzbot+fc8cd9a673d4577fb2e4@syzkaller.appspotmail.com,
	Dan Carpenter <dan.carpenter@oracle.com>,
	"David S . Miller" <davem@davemloft.net>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 33/43] net: 6pack: fix slab-out-of-bounds in decode_data
Date: Tue, 24 Aug 2021 13:06:04 -0400	[thread overview]
Message-ID: <20210824170614.710813-34-sashal@kernel.org> (raw)
In-Reply-To: <20210824170614.710813-1-sashal@kernel.org>

From: Pavel Skripkin <paskripkin@gmail.com>

[ Upstream commit 19d1532a187669ce86d5a2696eb7275310070793 ]

Syzbot reported slab-out-of bounds write in decode_data().
The problem was in missing validation checks.

Syzbot's reproducer generated malicious input, which caused
decode_data() to be called a lot in sixpack_decode(). Since
rx_count_cooked is only 400 bytes and noone reported before,
that 400 bytes is not enough, let's just check if input is malicious
and complain about buffer overrun.

Fail log:
==================================================================
BUG: KASAN: slab-out-of-bounds in drivers/net/hamradio/6pack.c:843
Write of size 1 at addr ffff888087c5544e by task kworker/u4:0/7

CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.6.0-rc3-syzkaller #0
...
Workqueue: events_unbound flush_to_ldisc
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:641
 __asan_report_store1_noabort+0x17/0x20 mm/kasan/generic_report.c:137
 decode_data.part.0+0x23b/0x270 drivers/net/hamradio/6pack.c:843
 decode_data drivers/net/hamradio/6pack.c:965 [inline]
 sixpack_decode drivers/net/hamradio/6pack.c:968 [inline]

Reported-and-tested-by: syzbot+fc8cd9a673d4577fb2e4@syzkaller.appspotmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/hamradio/6pack.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 03c96a6cbafd..e510dbda77e5 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -870,6 +870,12 @@ static void decode_data(struct sixpack *sp, unsigned char inbyte)
 		return;
 	}
 
+	if (sp->rx_count_cooked + 2 >= sizeof(sp->cooked_buf)) {
+		pr_err("6pack: cooked buffer overrun, data loss\n");
+		sp->rx_count = 0;
+		return;
+	}
+
 	buf = sp->raw_buf;
 	sp->cooked_buf[sp->rx_count_cooked++] =
 		buf[0] | ((buf[1] << 2) & 0xc0);
-- 
2.30.2


  parent reply	other threads:[~2021-08-24 17:37 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-24 17:05 [PATCH 4.9 00/43] 4.9.281-rc1 review Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 01/43] iio: adc: Fix incorrect exit of for-loop Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 02/43] ASoC: intel: atom: Fix reference to PCM buffer address Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 03/43] i2c: dev: zero out array used for i2c reads from userspace Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 04/43] ACPI: NFIT: Fix support for virtual SPA ranges Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 05/43] ppp: Fix generating ifname when empty IFLA_IFNAME is specified Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 06/43] net: Fix memory leak in ieee802154_raw_deliver Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 07/43] net: bridge: fix memleak in br_add_if() Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 08/43] tcp_bbr: fix u32 wrap bug in round logic if bbr_init() called after 2B packets Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 09/43] xen/events: Fix race in set_evtchn_to_irq Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 10/43] x86/tools: Fix objdump version check again Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 11/43] PCI/MSI: Enable and mask MSI-X early Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 12/43] PCI/MSI: Do not set invalid bits in MSI mask Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 13/43] PCI/MSI: Correct misleading comments Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 14/43] PCI/MSI: Use msi_mask_irq() in pci_msi_shutdown() Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 15/43] PCI/MSI: Protect msi_desc::masked for multi-MSI Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 16/43] PCI/MSI: Mask all unused MSI-X entries Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 17/43] PCI/MSI: Enforce that MSI-X table entry is masked for update Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 18/43] PCI/MSI: Enforce MSI[X] entry updates to be visible Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 19/43] vmlinux.lds.h: Handle clang's module.{c,d}tor sections Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 20/43] mac80211: drop data frames without key on encrypted links Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 21/43] KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653) Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 22/43] x86/fpu: Make init_fpstate correct with optimized XSAVE Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 23/43] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe() Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 24/43] ARM: dts: am43x-epos-evm: Reduce i2c0 bus speed for tps65218 Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 25/43] dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 26/43] scsi: megaraid_mm: Fix end of loop tests for list_for_each_entry() Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 27/43] scsi: scsi_dh_rdac: Avoid crash during rdac_bus_attach() Sasha Levin
2021-08-24 17:05 ` [PATCH 4.9 28/43] scsi: core: Avoid printing an error if target_alloc() returns -ENXIO Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 29/43] ARM: dts: nomadik: Fix up interrupt controller node names Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 30/43] Bluetooth: hidp: use correct wait queue when removing ctrl_wait Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 31/43] dccp: add do-while-0 stubs for dccp_pr_debug macros Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 32/43] vhost: Fix the calculation in vhost_overflow() Sasha Levin
2021-08-24 17:06 ` Sasha Levin [this message]
2021-08-24 17:06 ` [PATCH 4.9 34/43] net: qlcnic: add missed unlock in qlcnic_83xx_flash_read32 Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 35/43] mmc: dw_mmc: call the dw_mci_prep_stop_abort() by default Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 36/43] mmc: dw_mmc: Fix hang on data CRC error Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 37/43] ALSA: hda - fix the 'Capture Switch' value change notifications Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 38/43] ipack: tpci200: fix many double free issues in tpci200_pci_probe Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 39/43] btrfs: prevent rename2 from exchanging a subvol with a directory from different parents Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 40/43] ASoC: intel: atom: Fix breakage for PCM buffer address setup Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 41/43] locks: print a warning when mount fails due to lack of "mand" support Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 42/43] fs: warn about impending deprecation of mandatory locks Sasha Levin
2021-08-24 17:06 ` [PATCH 4.9 43/43] Linux 4.9.281-rc1 Sasha Levin
2021-08-25 20:26 ` [PATCH 4.9 00/43] 4.9.281-rc1 review Guenter Roeck
2021-08-25 21:17 ` Daniel Díaz
2021-08-25 22:37 ` Shuah Khan

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