net/9p: insulate the client against an invalid error code sent by a 9p server

A looney tunes server sending an invalid error code (which is !IS_ERR_VALUE)
can result in a client oops. So fix it by adding a check and converting unknown
or invalid error codes to -ESERVERFAULT.

Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This commit is contained in:
Abhishek Kulkarni 2009-08-17 16:38:45 -05:00 committed by Eric Van Hensbergen
parent 48559b4c30
commit 0aad37ef3d
2 changed files with 2 additions and 7 deletions

View file

@ -411,14 +411,9 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
if (c->dotu) if (c->dotu)
err = -ecode; err = -ecode;
if (!err) { if (!err || !IS_ERR_VALUE(err))
err = p9_errstr2errno(ename, strlen(ename)); err = p9_errstr2errno(ename, strlen(ename));
/* string match failed */
if (!err)
err = -ESERVERFAULT;
}
P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename); P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
kfree(ename); kfree(ename);

View file

@ -239,7 +239,7 @@ int p9_errstr2errno(char *errstr, int len)
errstr[len] = 0; errstr[len] = 0;
printk(KERN_ERR "%s: server reported unknown error %s\n", printk(KERN_ERR "%s: server reported unknown error %s\n",
__func__, errstr); __func__, errstr);
errno = 1; errno = ESERVERFAULT;
} }
return -errno; return -errno;