diff options
| author | Juergen Gross <jgross@suse.com> | 2021-11-29 10:45:11 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-01 09:27:44 +0100 |
| commit | bdef6fc5e725663f471ec1ff4c0350dae7b794c7 (patch) | |
| tree | 0b128d402b55d3d56730cf13643e462f53c8b59b | |
| parent | e4e01b0e4b7fca40586639647f83eaa21a0a8203 (diff) | |
tty: hvc: replace BUG_ON() with negative return value
commit e679004dec37566f658a255157d3aed9d762a2b7 upstream.
Xen frontends shouldn't BUG() in case of illegal data received from
their backends. So replace the BUG_ON()s when reading illegal data from
the ring page with negative return values.
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20210707091045.460-1-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/hvc/hvc_xen.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index dc43fa96c3de..7874aaf30ef4 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -86,7 +86,11 @@ static int __write_console(struct xencons_info *xencons, cons = intf->out_cons; prod = intf->out_prod; mb(); /* update queue values before going on */ - BUG_ON((prod - cons) > sizeof(intf->out)); + + if ((prod - cons) > sizeof(intf->out)) { + pr_err_once("xencons: Illegal ring page indices"); + return -EINVAL; + } while ((sent < len) && ((prod - cons) < sizeof(intf->out))) intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++]; @@ -114,7 +118,10 @@ static int domU_write_console(uint32_t vtermno, const char *data, int len) */ while (len) { int sent = __write_console(cons, data, len); - + + if (sent < 0) + return sent; + data += sent; len -= sent; @@ -138,7 +145,11 @@ static int domU_read_console(uint32_t vtermno, char *buf, int len) cons = intf->in_cons; prod = intf->in_prod; mb(); /* get pointers before reading ring */ - BUG_ON((prod - cons) > sizeof(intf->in)); + + if ((prod - cons) > sizeof(intf->in)) { + pr_err_once("xencons: Illegal ring page indices"); + return -EINVAL; + } while (cons != prod && recv < len) buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)]; |