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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jeff Dike <jdike@addtoit.com>,
	Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Richard Weinberger <richard@nod.at>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
	Alex Dewar <alex.dewar@gmx.co.uk>,
	linux-um@lists.infradead.org, bpf@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH] um:
Date: Tue, 28 Jan 2020 18:10:00 +0300	[thread overview]
Message-ID: <20200128151000.kx2bwayuuxpuqn6t@kili.mountain> (raw)
In-Reply-To: <de3bdae8-2dcd-490f-cdf2-67bf92a552e8@cambridgegreys.com>

1) The uml_vector_user_bpf() returns pointers so it should return NULL
   instead of false.
2) If the "bpf_prog" allocation failed, it would have eventually lead to
   a crash.  We can't succeed after the error happens so it should just
   return.

Fixes: 9807019a62dc ("um: Loadable BPF "Firmware" for vector drivers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: The first version broke the build.  Shame upon me.

 arch/um/drivers/vector_user.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index ddcd917be0af..1403cbadf92b 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -732,13 +732,14 @@ void *uml_vector_user_bpf(char *filename)
 
 	if (stat(filename, &statbuf) < 0) {
 		printk(KERN_ERR "Error %d reading bpf file", -errno);
-		return false;
+		return NULL;
 	}
 	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
-	if (bpf_prog != NULL) {
-		bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
-		bpf_prog->filter = NULL;
-	}
+	if (bpf_prog == NULL)
+		return NULL;
+	bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
+	bpf_prog->filter = NULL;
+
 	ffd = os_open_file(filename, of_read(OPENFLAGS()), 0);
 	if (ffd < 0) {
 		printk(KERN_ERR "Error %d opening bpf file", -errno);
-- 
2.11.0


WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jeff Dike <jdike@addtoit.com>,
	Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Richard Weinberger <richard@nod.at>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
	Alex Dewar <alex.dewar@gmx.co.uk>,
	linux-um@lists.infradead.org, bpf@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH v3] um: Fix some error handling in uml_vector_user_bpf()
Date: Tue, 28 Jan 2020 18:27:03 +0300	[thread overview]
Message-ID: <20200128151000.kx2bwayuuxpuqn6t@kili.mountain> (raw)
Message-ID: <20200128152703.53Nsc9Mh0PWaTGkVnCPZkAH95w7ysWrel5w1PR_eq0E@z> (raw)

1) The uml_vector_user_bpf() returns pointers so it should return NULL
   instead of false.
2) If the "bpf_prog" allocation failed, it would have eventually lead to
   a crash.  We can't succeed after the error happens so it should just
   return.

Fixes: 9807019a62dc ("um: Loadable BPF "Firmware" for vector drivers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v3: Fix screwed up subject.  Sorry.  Not my most shining hour.
v2: The first version broke the build.  Shame upon me.

 arch/um/drivers/vector_user.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index ddcd917be0af..1403cbadf92b 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -732,13 +732,14 @@ void *uml_vector_user_bpf(char *filename)
 
 	if (stat(filename, &statbuf) < 0) {
 		printk(KERN_ERR "Error %d reading bpf file", -errno);
-		return false;
+		return NULL;
 	}
 	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
-	if (bpf_prog != NULL) {
-		bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
-		bpf_prog->filter = NULL;
-	}
+	if (bpf_prog == NULL)
+		return NULL;
+	bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
+	bpf_prog->filter = NULL;
+
 	ffd = os_open_file(filename, of_read(OPENFLAGS()), 0);
 	if (ffd < 0) {
 		printk(KERN_ERR "Error %d opening bpf file", -errno);
-- 
2.11.0


  parent reply	other threads:[~2020-01-28 15:11 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-24 10:14 [PATCH] um: Fix some error handling in uml_vector_user_bpf() Dan Carpenter
2020-01-24 12:52 ` Anton Ivanov
2020-01-24 16:44   ` Dan Carpenter
2020-01-24 16:48     ` Anton Ivanov
2020-01-25  6:01       ` Dan Carpenter
2020-01-28 15:10       ` Dan Carpenter [this message]
2020-01-28 15:27         ` [PATCH v3] " Dan Carpenter
2020-02-10 14:17         ` Anton Ivanov

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