4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
commit 32a1fb36f6e50183871c2c1fcf5493c633e84732 upstream.
Change these free functions to allow passing NULL as the argument and
treat it as a no-op just like free(NULL) would.
Or, if rqst->rq_iov is NULL.
The second scenario could happen for smb2_queryfs() if the call
to SMB2_query_info_init() fails and we go to qfs_exit to clean up
and free all resources.
In that case we have not yet assigned rqst[2].rq_iov and thus
the rq_iov dereference in SMB2_close_free() will cause a NULL pointer
dereference.
[ bp: upstream patch also fixes SMB2_set_info_free which was introduced in 4.20 ]
Fixes: 1eb9fb52040f ("cifs: create SMB2_open_init()/SMB2_open_free() helpers")
Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Reviewed-by: Aurelien Aptel <aaptel@xxxxxxxx>
CC: Stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/cifs/smb2pdu.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2243,10 +2243,12 @@ SMB2_open_free(struct smb_rqst *rqst)
{
int i;
- cifs_small_buf_release(rqst->rq_iov[0].iov_base);
- for (i = 1; i < rqst->rq_nvec; i++)
- if (rqst->rq_iov[i].iov_base != smb2_padding)
- kfree(rqst->rq_iov[i].iov_base);
+ if (rqst && rqst->rq_iov) {
+ cifs_small_buf_release(rqst->rq_iov[0].iov_base);
+ for (i = 1; i < rqst->rq_nvec; i++)
+ if (rqst->rq_iov[i].iov_base != smb2_padding)
+ kfree(rqst->rq_iov[i].iov_base);
+ }
}
int
@@ -2535,7 +2537,8 @@ SMB2_close_init(struct cifs_tcon *tcon,
void
SMB2_close_free(struct smb_rqst *rqst)
{
- cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
+ if (rqst && rqst->rq_iov)
+ cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
}
int
@@ -2685,7 +2688,8 @@ SMB2_query_info_init(struct cifs_tcon *t
void
SMB2_query_info_free(struct smb_rqst *rqst)
{
- cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
+ if (rqst && rqst->rq_iov)
+ cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
}
static int
