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authorDaniel Starke <daniel.starke@siemens.com>2022-04-25 03:47:26 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-26 08:09:46 +0200
commit19317433057dc1f2ca9a975e4e6b547282c2a5ef (patch)
tree30f37c3b05088590e258a046256c04547fdba586 /drivers/tty/n_gsm.c
parent637674fa40059cddcc3ad2212728965072f62ea3 (diff)
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tty: n_gsm: fix sometimes uninitialized warning in gsm_dlci_modem_output()
'size' may be used uninitialized in gsm_dlci_modem_output() if called with an adaption that is neither 1 nor 2. The function is currently only called by gsm_modem_upd_via_data() and only for adaption 2. Properly handle every invalid case by returning -EINVAL to silence the compiler warning and avoid future regressions. Fixes: c19ffe00fed6 ("tty: n_gsm: fix invalid use of MSC in advanced option") Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220425104726.7986-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/n_gsm.c')
-rw-r--r--drivers/tty/n_gsm.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 8652308c187f..a38b922bcbc1 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -932,18 +932,21 @@ static int gsm_dlci_modem_output(struct gsm_mux *gsm, struct gsm_dlci *dlci,
{
u8 *dp = NULL;
struct gsm_msg *msg;
- int size;
+ int size = 0;
/* for modem bits without break data */
- if (dlci->adaption == 1) {
- size = 0;
- } else if (dlci->adaption == 2) {
- size = 1;
+ switch (dlci->adaption) {
+ case 1: /* Unstructured */
+ break;
+ case 2: /* Unstructured with modem bits. */
+ size++;
if (brk > 0)
size++;
- } else {
+ break;
+ default:
pr_err("%s: unsupported adaption %d\n", __func__,
dlci->adaption);
+ return -EINVAL;
}
msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);