lkml.org 
[lkml]   [2020]   [Aug]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] nfs: Fix getxattr kernel panic and memory overflow
Date
Move the buffer size check to decode_attr_security_label() before memcpy()
Only call memcpy() if the buffer is large enough

Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@starlab.io>
---
fs/nfs/nfs4proc.c | 2 --
fs/nfs/nfs4xdr.c | 5 ++++-
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2e2dac29a9e9..45e0585e0667 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5845,8 +5845,6 @@ static int _nfs4_get_security_label(struct inode *inode, void *buf,
return ret;
if (!(fattr.valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL))
return -ENOENT;
- if (buflen < label.len)
- return -ERANGE;
return 0;
}

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 47817ef0aadb..50162e0a959c 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -4166,7 +4166,10 @@ static int decode_attr_security_label(struct xdr_stream *xdr, uint32_t *bitmap,
return -EIO;
if (len < NFS4_MAXLABELLEN) {
if (label) {
- memcpy(label->label, p, len);
+ if (label->len && label->len < len)
+ return -ERANGE;
+ if (label->len)
+ memcpy(label->label, p, len);
label->len = len;
label->pi = pi;
label->lfs = lfs;
--
2.25.1
\
 
 \ /
  Last update: 2020-08-05 21:25    [W:0.119 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site