lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20190527005034.GA16907@zhanggen-UX430UQ>
Date:   Mon, 27 May 2019 08:50:34 +0800
From:   Gen Zhang <blackgod016574@...il.com>
To:     agk@...hat.com, snitzer@...hat.com
Cc:     dm-devel@...hat.com, linux-kernel@...r.kernel.org
Subject: [PATCH] dm-region-hash: fix a missing-check bug in __rh_alloc()

In function __rh_alloc(), the pointer nreg is allocated a memory space
via kmalloc(). And it is used in the following codes. However, when 
there is a memory allocation error, kmalloc() fails. Thus null pointer
dereference may happen. And it will cause the kernel to crash. Therefore,
we should check the return value and handle the error.
Further, in __rh_find(), we should also check the return value and
handle the error.

Signed-off-by: Gen Zhang <blackgod016574@...il.com>
---
diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c
index 1f76045..2fa1641 100644
--- a/drivers/md/dm-region-hash.c
+++ b/drivers/md/dm-region-hash.c
@@ -290,8 +290,11 @@ static struct dm_region *__rh_alloc(struct dm_region_hash *rh, region_t region)
 	struct dm_region *reg, *nreg;
 
 	nreg = mempool_alloc(&rh->region_pool, GFP_ATOMIC);
-	if (unlikely(!nreg))
+	if (unlikely(!nreg)) {
 		nreg = kmalloc(sizeof(*nreg), GFP_NOIO | __GFP_NOFAIL);
+		if (!nreg)
+			return NULL;
+	}
 
 	nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?
 		      DM_RH_CLEAN : DM_RH_NOSYNC;
@@ -329,6 +332,8 @@ static struct dm_region *__rh_find(struct dm_region_hash *rh, region_t region)
 	if (!reg) {
 		read_unlock(&rh->hash_lock);
 		reg = __rh_alloc(rh, region);
+		if (!reg)
+			return NULL;
 		read_lock(&rh->hash_lock);
 	}
 
---

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ