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cifs: don't leak -EAGAIN for stat() during reconnect

commit fc513fac56 upstream.

If from cifs_revalidate_dentry_attr() the SMB2/QUERY_INFO call fails with an
error, such as STATUS_SESSION_EXPIRED, causing the session to be reconnected
it is possible we will leak -EAGAIN back to the application even for
system calls such as stat() where this is not a valid error.

Fix this by re-trying the operation from within cifs_revalidate_dentry_attr()
if cifs_get_inode_info*() returns -EAGAIN.

This fixes stat() and possibly also other system calls that uses
cifs_revalidate_dentry*().

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Ronnie Sahlberg 2020-02-19 06:01:03 +10:00 committed by Greg Kroah-Hartman
parent 6369c1e0b6
commit 98cc1bd575
1 changed files with 5 additions and 1 deletions

View File

@ -2011,6 +2011,7 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry)
struct inode *inode = d_inode(dentry);
struct super_block *sb = dentry->d_sb;
char *full_path = NULL;
int count = 0;
if (inode == NULL)
return -ENOENT;
@ -2032,15 +2033,18 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry)
full_path, inode, inode->i_count.counter,
dentry, cifs_get_time(dentry), jiffies);
again:
if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);
else
rc = cifs_get_inode_info(&inode, full_path, NULL, sb,
xid, NULL);
if (rc == -EAGAIN && count++ < 10)
goto again;
out:
kfree(full_path);
free_xid(xid);
return rc;
}