lkml.org 
[lkml]   [2020]   [Jun]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] Fix null pointer dereference in vector_user_bpf
Date
The bpf_prog is being checked for !NULL after uml_kmalloc
but later its used directly for example:
bpf_prog->filter = bpf and is also later returned upon
success. Fix this, do a NULL check and return right away.

Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
---
arch/um/drivers/vector_user.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index c4a0f26b2824..0e6d6717bf73 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -789,10 +789,12 @@ void *uml_vector_user_bpf(char *filename)
return false;
}
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) {
+ printk(KERN_ERR "Failed to allocate bpf prog buffer");
+ 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);
--
2.17.1
\
 
 \ /
  Last update: 2020-06-14 03:21    [W:0.058 / U:2.620 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site