| Message ID | 20190131124607.2458-1-aaptel@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | CIFS: fix use-after-free of the lease keys | expand |
Aurelien Aptel <aaptel@suse.com> writes: > The request buffers are freed right before copying the pointers. > Use the func args instead which are identical and still valid. > > Simple reproducer (requires KASAN enabled) on a cifs mount: > > echo foo > foo ; tail -f foo & rm foo > > Cc: <stable@vger.kernel.org> # 4.20 > Fixes: 179e44d49c2f ("smb3: add tracepoint for sending lease break responses to server") > Signed-off-by: Aurelien Aptel <aaptel@suse.com> > --- > fs/cifs/smb2pdu.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c > index 846e605175bf..54181387a770 100644 > --- a/fs/cifs/smb2pdu.c > +++ b/fs/cifs/smb2pdu.c > @@ -4435,8 +4435,8 @@ SMB2_lease_break(const unsigned int xid, struct cifs_tcon *tcon, > rc = cifs_send_recv(xid, ses, &rqst, &resp_buf_type, flags, &rsp_iov); > cifs_small_buf_release(req); > > - please_key_low = (__u64 *)req->LeaseKey; > - please_key_high = (__u64 *)(req->LeaseKey+8); > + please_key_low = (__u64 *)lease_key; > + please_key_high = (__u64 *)(lease_key+8); > if (rc) { > cifs_stats_fail_inc(tcon, SMB2_OPLOCK_BREAK_HE); > trace_smb3_lease_err(le32_to_cpu(lease_state), tcon->tid, > -- > 2.16.4 Reviewed-by: Paulo Alcantara <palcantara@suse.de> Thanks! Paulo
Moved into cifs-2.6.git for-next On Thu, Jan 31, 2019 at 6:53 AM Paulo Alcantara <paulo@paulo.ac> wrote: > > Aurelien Aptel <aaptel@suse.com> writes: > > > The request buffers are freed right before copying the pointers. > > Use the func args instead which are identical and still valid. > > > > Simple reproducer (requires KASAN enabled) on a cifs mount: > > > > echo foo > foo ; tail -f foo & rm foo > > > > Cc: <stable@vger.kernel.org> # 4.20 > > Fixes: 179e44d49c2f ("smb3: add tracepoint for sending lease break responses to server") > > Signed-off-by: Aurelien Aptel <aaptel@suse.com> > > --- > > fs/cifs/smb2pdu.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c > > index 846e605175bf..54181387a770 100644 > > --- a/fs/cifs/smb2pdu.c > > +++ b/fs/cifs/smb2pdu.c > > @@ -4435,8 +4435,8 @@ SMB2_lease_break(const unsigned int xid, struct cifs_tcon *tcon, > > rc = cifs_send_recv(xid, ses, &rqst, &resp_buf_type, flags, &rsp_iov); > > cifs_small_buf_release(req); > > > > - please_key_low = (__u64 *)req->LeaseKey; > > - please_key_high = (__u64 *)(req->LeaseKey+8); > > + please_key_low = (__u64 *)lease_key; > > + please_key_high = (__u64 *)(lease_key+8); > > if (rc) { > > cifs_stats_fail_inc(tcon, SMB2_OPLOCK_BREAK_HE); > > trace_smb3_lease_err(le32_to_cpu(lease_state), tcon->tid, > > -- > > 2.16.4 > > Reviewed-by: Paulo Alcantara <palcantara@suse.de> > > Thanks! > Paulo
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 846e605175bf..54181387a770 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -4435,8 +4435,8 @@ SMB2_lease_break(const unsigned int xid, struct cifs_tcon *tcon, rc = cifs_send_recv(xid, ses, &rqst, &resp_buf_type, flags, &rsp_iov); cifs_small_buf_release(req); - please_key_low = (__u64 *)req->LeaseKey; - please_key_high = (__u64 *)(req->LeaseKey+8); + please_key_low = (__u64 *)lease_key; + please_key_high = (__u64 *)(lease_key+8); if (rc) { cifs_stats_fail_inc(tcon, SMB2_OPLOCK_BREAK_HE); trace_smb3_lease_err(le32_to_cpu(lease_state), tcon->tid,
The request buffers are freed right before copying the pointers. Use the func args instead which are identical and still valid. Simple reproducer (requires KASAN enabled) on a cifs mount: echo foo > foo ; tail -f foo & rm foo Cc: <stable@vger.kernel.org> # 4.20 Fixes: 179e44d49c2f ("smb3: add tracepoint for sending lease break responses to server") Signed-off-by: Aurelien Aptel <aaptel@suse.com> --- fs/cifs/smb2pdu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)