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| author | Daniel Starke <daniel.starke@siemens.com> | 2022-04-25 03:47:26 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-09 09:16:33 +0200 |
| commit | e578ba015ce8a495ecbb03597c8b30c40841b6bb (patch) | |
| tree | 0e2503c85b92f2098739818ab9282574fc14e162 | |
| parent | a5e357c8e7c252ba7421d6c0323012d08251603a (diff) | |
| download | linux-stable-e578ba015ce8a495ecbb03597c8b30c40841b6bb.tar.gz linux-stable-e578ba015ce8a495ecbb03597c8b30c40841b6bb.tar.bz2 linux-stable-e578ba015ce8a495ecbb03597c8b30c40841b6bb.zip | |
tty: n_gsm: fix sometimes uninitialized warning in gsm_dlci_modem_output()
commit 19317433057dc1f2ca9a975e4e6b547282c2a5ef upstream.
'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>
| -rw-r--r-- | drivers/tty/n_gsm.c | 15 |
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); |