From: Bryan Wu <[email protected]>
This bug was caught by LTP testcase fchmod06 on Blackfin platform.
In the manpage of fchmod, "EPERM: The effective UID does not match the
owner of the file, and the process is not privileged (Linux: it does not
have the CAP_FOWNER capability)."
But the ramfs nommu code missed the inode_change_ok POSIX UID/GID
verification. This patch fixed this.
Signed-off-by: Bryan Wu <[email protected]>
Cc: David Howells <[email protected]>
---
fs/ramfs/file-nommu.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 9345a46..5d258c4 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -195,6 +195,11 @@ static int ramfs_nommu_setattr(struct dentry *dentry, struct iattr *ia)
unsigned int old_ia_valid = ia->ia_valid;
int ret = 0;
+ /* POSIX UID/GID verification for setting inode attributes */
+ ret = inode_change_ok(inode, ia);
+ if (ret)
+ return ret;
+
/* by providing our own setattr() method, we skip this quotaism */
if ((old_ia_valid & ATTR_UID && ia->ia_uid != inode->i_uid) ||
(old_ia_valid & ATTR_GID && ia->ia_gid != inode->i_gid))
--
1.5.2