| Message ID | 20210612144407.60259-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: dsa: b53: Fix dereference of null dev | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/subject_prefix | warning | Target tree name not specified in the subject |
| netdev/cc_maintainers | success | CCed 7 of 7 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 16 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
On Sat, Jun 12, 2021 at 03:44:07PM +0100, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > Currently pointer priv is dereferencing dev before dev is being null > checked so a potential null pointer dereference can occur. Fix this > by only assigning and using priv if dev is not-null. > > Addresses-Coverity: ("Dereference before null check") > Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts") > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/net/dsa/b53/b53_srab.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c > index aaa12d73784e..e77ac598f859 100644 > --- a/drivers/net/dsa/b53/b53_srab.c > +++ b/drivers/net/dsa/b53/b53_srab.c > @@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev) > static int b53_srab_remove(struct platform_device *pdev) > { > struct b53_device *dev = platform_get_drvdata(pdev); > - struct b53_srab_priv *priv = dev->priv; > > - b53_srab_intr_set(priv, false); > - if (dev) > + if (dev) { > + struct b53_srab_priv *priv = dev->priv; > + > + b53_srab_intr_set(priv, false); > b53_switch_remove(dev); > + } > > return 0; > } > -- > 2.31.1 > I think the better question is how can "dev" be NULL in the first place, since b53_srab_probe() does an unconditional platform_set_drvdata() with what appears to be a non-NULL dev.
On Sat, Jun 12, 2021 at 03:44:07PM +0100, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > Currently pointer priv is dereferencing dev before dev is being null > checked so a potential null pointer dereference can occur. Fix this > by only assigning and using priv if dev is not-null. > > Addresses-Coverity: ("Dereference before null check") > Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts") > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/net/dsa/b53/b53_srab.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c > index aaa12d73784e..e77ac598f859 100644 > --- a/drivers/net/dsa/b53/b53_srab.c > +++ b/drivers/net/dsa/b53/b53_srab.c > @@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev) > static int b53_srab_remove(struct platform_device *pdev) > { > struct b53_device *dev = platform_get_drvdata(pdev); > - struct b53_srab_priv *priv = dev->priv; > > - b53_srab_intr_set(priv, false); > - if (dev) > + if (dev) { This is the remove function and "dev" can't be NULL at this point. Better to just remove the NULL check. regards, dan carpenter
On 14/06/2021 12:28, Dan Carpenter wrote: > On Sat, Jun 12, 2021 at 03:44:07PM +0100, Colin King wrote: >> From: Colin Ian King <colin.king@canonical.com> >> >> Currently pointer priv is dereferencing dev before dev is being null >> checked so a potential null pointer dereference can occur. Fix this >> by only assigning and using priv if dev is not-null. >> >> Addresses-Coverity: ("Dereference before null check") >> Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts") >> Signed-off-by: Colin Ian King <colin.king@canonical.com> >> --- >> drivers/net/dsa/b53/b53_srab.c | 8 +++++--- >> 1 file changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c >> index aaa12d73784e..e77ac598f859 100644 >> --- a/drivers/net/dsa/b53/b53_srab.c >> +++ b/drivers/net/dsa/b53/b53_srab.c >> @@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev) >> static int b53_srab_remove(struct platform_device *pdev) >> { >> struct b53_device *dev = platform_get_drvdata(pdev); >> - struct b53_srab_priv *priv = dev->priv; >> >> - b53_srab_intr_set(priv, false); >> - if (dev) >> + if (dev) { > > This is the remove function and "dev" can't be NULL at this point. > Better to just remove the NULL check. Will do. > > regards, > dan carpenter >
diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c index aaa12d73784e..e77ac598f859 100644 --- a/drivers/net/dsa/b53/b53_srab.c +++ b/drivers/net/dsa/b53/b53_srab.c @@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev) static int b53_srab_remove(struct platform_device *pdev) { struct b53_device *dev = platform_get_drvdata(pdev); - struct b53_srab_priv *priv = dev->priv; - b53_srab_intr_set(priv, false); - if (dev) + if (dev) { + struct b53_srab_priv *priv = dev->priv; + + b53_srab_intr_set(priv, false); b53_switch_remove(dev); + } return 0; }