| Message ID | 1542786111-18648-1-git-send-email-wen.yang99@zte.com.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
Le 21/11/2018 à 08:41, Wen Yang a écrit : > This patch fixes a possible null pointer dereference in > ucc_of_parse_tdm, detected by the semantic patch > deref_null.cocci, with the following warning: > > ./drivers/soc/fsl/qe/qe_tdm.c:177:21-24: ERROR: pdev is NULL but dereferenced. > > The following code has potential null pointer references: > pdev = of_find_device_by_node(np2); > if (!pdev) { > ret = -EINVAL; > pr_err("%pOFn: failed to lookup pdev\n", np2); > of_node_put(np2); > goto err_miss_siram_property; > } > ... > err_miss_siram_property: > devm_iounmap(&pdev->dev, utdm->si_regs); > > Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> > Reviewed-by: Tan Hu <tan.hu@zte.com.cn> > CC: Julia Lawall <julia.lawall@lip6.fr> > --- > drivers/soc/fsl/qe/qe_tdm.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/soc/fsl/qe/qe_tdm.c b/drivers/soc/fsl/qe/qe_tdm.c > index f78c346..166378b 100644 > --- a/drivers/soc/fsl/qe/qe_tdm.c > +++ b/drivers/soc/fsl/qe/qe_tdm.c > @@ -174,7 +174,8 @@ int ucc_of_parse_tdm(struct device_node *np, struct ucc_tdm *utdm, > return ret; > > err_miss_siram_property: > - devm_iounmap(&pdev->dev, utdm->si_regs); > + if (pdev) > + devm_iounmap(&pdev->dev, utdm->si_regs); You are just hiding the issue, not fixing it. The problem is that pdev gets modified, so in any case that devm_iounmap() will fail even when the new pdev is valid, because the iomap was done with a different pdev. Christophe > return ret; > } > EXPORT_SYMBOL(ucc_of_parse_tdm); >
diff --git a/drivers/soc/fsl/qe/qe_tdm.c b/drivers/soc/fsl/qe/qe_tdm.c index f78c346..166378b 100644 --- a/drivers/soc/fsl/qe/qe_tdm.c +++ b/drivers/soc/fsl/qe/qe_tdm.c @@ -174,7 +174,8 @@ int ucc_of_parse_tdm(struct device_node *np, struct ucc_tdm *utdm, return ret; err_miss_siram_property: - devm_iounmap(&pdev->dev, utdm->si_regs); + if (pdev) + devm_iounmap(&pdev->dev, utdm->si_regs); return ret; } EXPORT_SYMBOL(ucc_of_parse_tdm);
This patch fixes a possible null pointer dereference in ucc_of_parse_tdm, detected by the semantic patch deref_null.cocci, with the following warning: ./drivers/soc/fsl/qe/qe_tdm.c:177:21-24: ERROR: pdev is NULL but dereferenced. The following code has potential null pointer references: pdev = of_find_device_by_node(np2); if (!pdev) { ret = -EINVAL; pr_err("%pOFn: failed to lookup pdev\n", np2); of_node_put(np2); goto err_miss_siram_property; } ... err_miss_siram_property: devm_iounmap(&pdev->dev, utdm->si_regs); Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Reviewed-by: Tan Hu <tan.hu@zte.com.cn> CC: Julia Lawall <julia.lawall@lip6.fr> --- drivers/soc/fsl/qe/qe_tdm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)