[PATCH v3 08/13] vfs: copy_file_range needs to strip setuid bits and update timestamps

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Because generic_copy_file_range doesn't hold the destination inode lock
throughout the copy, strip setuid bits before and after copy.

The destination inode mtime is updated before and after the copy and the
source inode atime is updated after the copy, similar to
generic_file_read_iter().

Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
 fs/read_write.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index cec7e7b1f693..706ea5f276a7 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1590,8 +1590,27 @@ ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
 				struct file *file_out, loff_t pos_out,
 				size_t len, unsigned int flags)
 {
-	return do_splice_direct(file_in, &pos_in, file_out, &pos_out,
-				len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
+	struct inode *inode_out = file_inode(file_out);
+	int ret, err;
+
+	/* Should inode_out lock be held throughout the copy operation? */
+	inode_lock(inode_out);
+	err = file_modified(file_out);
+	inode_unlock(inode_out);
+	if (err)
+		return err;
+
+	ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
+			       len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
+
+	file_accessed(file_in);
+
+	/* To be on the safe side, remove privs also after copy */
+	inode_lock(inode_out);
+	err = file_modified(file_out);
+	inode_unlock(inode_out);
+
+	return err ?: ret;
 }
 EXPORT_SYMBOL(generic_copy_file_range);
 
-- 
2.17.1




[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]

  Powered by Linux