Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.15 132/230] tty: n_gsm: fix sometimes uninitialized warning in gsm_dlci_modem_output() | Date | Mon, 11 Jul 2022 11:06:28 +0200 |
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From: Daniel Starke <daniel.starke@siemens.com>
[ Upstream commit 19317433057dc1f2ca9a975e4e6b547282c2a5ef ]
'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> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/tty/n_gsm.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index c8ca00fad8e4..fd4a86111a6e 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -945,18 +945,21 @@ 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); -- 2.35.1
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