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| author | Ronnie Sahlberg <lsahlber@redhat.com> | 2018-10-24 11:50:33 +1000 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2018-10-24 07:21:41 -0500 |
| commit | 32a1fb36f6e50183871c2c1fcf5493c633e84732 (patch) | |
| tree | ab417190efe7b6e03b36cfaf91ec4b47ff807f36 /fs/cifs/smb2pdu.c | |
| parent | 35a908072311b8efce8467161ea870cd410a1d68 (diff) | |
| download | lwn-32a1fb36f6e50183871c2c1fcf5493c633e84732.tar.gz lwn-32a1fb36f6e50183871c2c1fcf5493c633e84732.zip | |
cifs: allow calling SMB2_xxx_free(NULL)
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.
Fixes: 1eb9fb52040f ("cifs: create SMB2_open_init()/SMB2_open_free() helpers")
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Diffstat (limited to 'fs/cifs/smb2pdu.c')
| -rw-r--r-- | fs/cifs/smb2pdu.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 5a08c8f6a322..7d7b016fe8bb 100644 --- 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 @@ -2536,7 +2538,8 @@ SMB2_close_init(struct cifs_tcon *tcon, struct smb_rqst *rqst, 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 @@ -2689,7 +2692,8 @@ SMB2_query_info_init(struct cifs_tcon *tcon, struct smb_rqst *rqst, 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 @@ -3803,7 +3807,8 @@ SMB2_set_info_init(struct cifs_tcon *tcon, struct smb_rqst *rqst, void SMB2_set_info_free(struct smb_rqst *rqst) { - cifs_buf_release(rqst->rq_iov[0].iov_base); /* request */ + if (rqst && rqst->rq_iov) + cifs_buf_release(rqst->rq_iov[0].iov_base); /* request */ } static int |