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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jia-Ju Bai <baijiaju1990@gmail.com>,
	Casey Schaufler <casey@schaufler-ca.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-security-module@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 16/23] security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb()
Date: Sun, 29 Sep 2019 13:35:26 -0400	[thread overview]
Message-ID: <20190929173535.9744-16-sashal@kernel.org> (raw)
In-Reply-To: <20190929173535.9744-1-sashal@kernel.org>

From: Jia-Ju Bai <baijiaju1990@gmail.com>

[ Upstream commit 3f4287e7d98a2954f20bf96c567fdffcd2b63eb9 ]

In smack_socket_sock_rcv_skb(), there is an if statement
on line 3920 to check whether skb is NULL:
    if (skb && skb->secmark != 0)

This check indicates skb can be NULL in some cases.

But on lines 3931 and 3932, skb is used:
    ad.a.u.net->netif = skb->skb_iif;
    ipv6_skb_to_auditdata(skb, &ad.a, NULL);

Thus, possible null-pointer dereferences may occur when skb is NULL.

To fix these possible bugs, an if statement is added to check skb.

These bugs are found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/smack/smack_lsm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 0d5ce7190b17e..09119c43525ed 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4031,6 +4031,8 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 			skp = smack_ipv6host_label(&sadd);
 		if (skp == NULL)
 			skp = smack_net_ambient;
+		if (skb == NULL)
+			break;
 #ifdef CONFIG_AUDIT
 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
 		ad.a.u.net->family = family;
-- 
2.20.1


  parent reply	other threads:[~2019-09-29 17:38 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-29 17:35 [PATCH AUTOSEL 4.14 01/23] clk: jz4740: Add TCU clock Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 02/23] MIPS: tlbex: Explicitly cast _PAGE_NO_EXEC to a boolean Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 03/23] i2c-cht-wc: Fix lockdep warning Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 04/23] mfd: intel-lpss: Remove D3cold delay Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 05/23] PCI: tegra: Fix OF node reference leak Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 06/23] livepatch: Nullify obj->mod in klp_module_coming()'s error path Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 07/23] ARM: 8898/1: mm: Don't treat faults reported from cache maintenance as writes Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 08/23] ARM: 8875/1: Kconfig: default to AEABI w/ Clang Sasha Levin
2019-09-29 18:08   ` Nathan Chancellor
2019-10-05 23:02     ` Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 09/23] MIPS: lantiq: update the clock alias' for the mainline PCIe PHY driver Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 10/23] firmware: bcm47xx_nvram: Correct size_t printf format Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 11/23] rtc: snvs: fix possible race condition Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 12/23] HID: apple: Fix stuck function keys when using FN Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 13/23] PCI: rockchip: Propagate errors for optional regulators Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 14/23] PCI: imx6: " Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 15/23] PCI: exynos: Propagate errors for optional PHYs Sasha Levin
2019-09-29 17:35 ` Sasha Levin [this message]
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 17/23] ARM: 8903/1: ensure that usable memory in bank 0 starts from a PMD-aligned address Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 18/23] fat: work around race with userspace's read via blockdev while mounting Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 19/23] pktcdvd: remove warning on attempting to register non-passthrough dev Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 20/23] hypfs: Fix error number left in struct pointer member Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 21/23] kbuild: clean compressed initramfs image Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 22/23] ocfs2: wait for recovering done after direct unlock request Sasha Levin
2019-09-29 17:35 ` [PATCH AUTOSEL 4.14 23/23] kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K Sasha Levin

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