[PATCH 3/6][TAKE7] revalidate write permissions for fallocate

Amit K. Arora
2007-07-13T12:48:47Z

From: David P. Quigley <dpquigl@tycho.nsa.gov>

Revalidate the write permissions for fallocate(2), in case security policy has
changed since the files were opened.

Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>

---
fs/open.c | 3 +++
1 files changed, 3 insertions(+)

Index: linux-2.6.22/fs/open.c
===================================================================
--- linux-2.6.22.orig/fs/open.c
+++ linux-2.6.22/fs/open.c
@@ -407,6 +407,9 @@ asmlinkage long sys_fallocate(int fd, in
goto out;
if (!(file->f_mode & FMODE_WRITE))
goto out_fput;
+ ret = security_file_permission(file, MAY_WRITE);
+ if (ret)
+ goto out_fput;

inode = file->f_path.dentry->d_inode;