[PATCH 3.2 149/152] splice: Apply generic position and size checks to each write

2015-02-16 Thread Ben Hutchings
3.2.67-rc1 review patch.  If anyone has any objections, please let me know.

--

From: Ben Hutchings 

We need to check the position and size of file writes against various
limits, using generic_write_check().  This was not being done for
the splice write path.  It was fixed upstream by commit 8d0207652cbe
("->splice_write() via ->write_iter()") but we can't apply that.

CVE-2014-7822

Signed-off-by: Ben Hutchings 
---
 fs/ocfs2/file.c | 8 ++--
 fs/splice.c | 8 ++--
 2 files changed, 12 insertions(+), 4 deletions(-)

--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2468,9 +2468,7 @@ static ssize_t ocfs2_file_splice_write(s
struct address_space *mapping = out->f_mapping;
struct inode *inode = mapping->host;
struct splice_desc sd = {
-   .total_len = len,
.flags = flags,
-   .pos = *ppos,
.u.file = out,
};
 
@@ -2480,6 +2478,12 @@ static ssize_t ocfs2_file_splice_write(s
out->f_path.dentry->d_name.len,
out->f_path.dentry->d_name.name, len);
 
+   ret = generic_write_checks(out, ppos, , 0);
+   if (ret)
+   return ret;
+   sd.total_len = len;
+   sd.pos = *ppos;
+
if (pipe->inode)
mutex_lock_nested(>inode->i_mutex, I_MUTEX_PARENT);
 
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1013,13 +1013,17 @@ generic_file_splice_write(struct pipe_in
struct address_space *mapping = out->f_mapping;
struct inode *inode = mapping->host;
struct splice_desc sd = {
-   .total_len = len,
.flags = flags,
-   .pos = *ppos,
.u.file = out,
};
ssize_t ret;
 
+   ret = generic_write_checks(out, ppos, , S_ISBLK(inode->i_mode));
+   if (ret)
+   return ret;
+   sd.total_len = len;
+   sd.pos = *ppos;
+
pipe_lock(pipe);
 
splice_from_pipe_begin();

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[PATCH 3.2 149/152] splice: Apply generic position and size checks to each write

2015-02-16 Thread Ben Hutchings
3.2.67-rc1 review patch.  If anyone has any objections, please let me know.

--

From: Ben Hutchings b...@decadent.org.uk

We need to check the position and size of file writes against various
limits, using generic_write_check().  This was not being done for
the splice write path.  It was fixed upstream by commit 8d0207652cbe
(-splice_write() via -write_iter()) but we can't apply that.

CVE-2014-7822

Signed-off-by: Ben Hutchings b...@decadent.org.uk
---
 fs/ocfs2/file.c | 8 ++--
 fs/splice.c | 8 ++--
 2 files changed, 12 insertions(+), 4 deletions(-)

--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2468,9 +2468,7 @@ static ssize_t ocfs2_file_splice_write(s
struct address_space *mapping = out-f_mapping;
struct inode *inode = mapping-host;
struct splice_desc sd = {
-   .total_len = len,
.flags = flags,
-   .pos = *ppos,
.u.file = out,
};
 
@@ -2480,6 +2478,12 @@ static ssize_t ocfs2_file_splice_write(s
out-f_path.dentry-d_name.len,
out-f_path.dentry-d_name.name, len);
 
+   ret = generic_write_checks(out, ppos, len, 0);
+   if (ret)
+   return ret;
+   sd.total_len = len;
+   sd.pos = *ppos;
+
if (pipe-inode)
mutex_lock_nested(pipe-inode-i_mutex, I_MUTEX_PARENT);
 
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1013,13 +1013,17 @@ generic_file_splice_write(struct pipe_in
struct address_space *mapping = out-f_mapping;
struct inode *inode = mapping-host;
struct splice_desc sd = {
-   .total_len = len,
.flags = flags,
-   .pos = *ppos,
.u.file = out,
};
ssize_t ret;
 
+   ret = generic_write_checks(out, ppos, len, S_ISBLK(inode-i_mode));
+   if (ret)
+   return ret;
+   sd.total_len = len;
+   sd.pos = *ppos;
+
pipe_lock(pipe);
 
splice_from_pipe_begin(sd);

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Please read the FAQ at  http://www.tux.org/lkml/