iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

NFS: Don't ignore suid/sgid bit changes after a successful write

Browse Source 
If we suspect that the server may have cleared the suid/sgid bit,
then mark the inode for revalidation.

Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2014-04-13 11:11:31 -04:00
parent 43b6535e71
commit 1f2edbe3fe
1 changed files with 33 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
fs/nfs/write.c
View File

@ -1353,6 +1353,30 @@ static const struct rpc_call_ops nfs_write_common_ops = {
.rpc_release = nfs_writeback_release_common,
};
/*
* Special version of should_remove_suid() that ignores capabilities.
*/
static int nfs_should_remove_suid(const struct inode *inode)
{
umode_t mode = inode->i_mode;
int kill = 0;
/* suid always must be killed */
if (unlikely(mode & S_ISUID))
kill = ATTR_KILL_SUID;
/*
* sgid without any exec bits is just a mandatory locking mark; leave
* it alone. If some exec bits are set, it's a real sgid; kill it.
*/
if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
kill |= ATTR_KILL_SGID;
if (unlikely(kill && S_ISREG(mode)))
return kill;
return 0;
}
/*
* This function is called when the WRITE call is complete.
@ -1401,9 +1425,16 @@ void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
}
}
#endif
if (task->tk_status < 0)
if (task->tk_status < 0) {
nfs_set_pgio_error(data->header, task->tk_status, argp->offset);
else if (resp->count < argp->count) {
return;
}
/* Deal with the suid/sgid bit corner case */
if (nfs_should_remove_suid(inode))
nfs_mark_for_revalidate(inode);
if (resp->count < argp->count) {
static unsigned long complain;
/* This a short write! */