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| author | Juergen Gross <jgross@suse.com> | 2021-11-29 12:25:57 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-08 08:46:53 +0100 |
| commit | 875475219ef95135e212f5fb902246cefa9fee15 (patch) | |
| tree | feff98b9e855a189bd772a8fc8bd75457d48f009 /drivers | |
| parent | db954a52438db8d8d3c7431c6ebd37f6aa771f63 (diff) | |
| download | linux-stable-875475219ef95135e212f5fb902246cefa9fee15.tar.gz linux-stable-875475219ef95135e212f5fb902246cefa9fee15.tar.bz2 linux-stable-875475219ef95135e212f5fb902246cefa9fee15.zip | |
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>
Diffstat (limited to 'drivers')
| -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 5e87e4866bcb..858c7b4b197c 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -99,7 +99,11 @@ 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++]; @@ -127,7 +131,10 @@ 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; @@ -151,7 +158,11 @@ 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)]; |