diff mbox series

[net-next,4/6,v7] net: dsa: rtl8366rb: Fix off-by-one bug

Message ID 20210925225929.2082046-5-linus.walleij@linaro.org (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series RTL8366(RB) cleanups part 1 | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 8 of 8 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, 8 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

Linus Walleij Sept. 25, 2021, 10:59 p.m. UTC
The max VLAN number with non-4K VLAN activated is 15, and the
range is 0..15. Not 16.

The impact should be low since we by default have 4K VLAN and
thus have 4095 VLANs to play with in this switch. There will
not be a problem unless the code is rewritten to only use
16 VLANs.

Fixes: d8652956cf37 ("net: dsa: realtek-smi: Add Realtek SMI driver")
Cc: Mauri Sandberg <sandberg@mailfence.com>
Cc: DENG Qingfang <dqfext@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v6->v7:
- Collect Alvin's and Vladimir's review tags.
ChangeLog v5->v6:
- No changes just resending with the rest of the
  patches.
ChangeLog v4->v5:
- Add some more text describing that this is not a critical bug.
- Add Fixes tag
ChangeLog v1->v4:
- New patch for a bug discovered when fixing the other issues.
---
 drivers/net/dsa/rtl8366rb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Florian Fainelli Sept. 26, 2021, 2:32 a.m. UTC | #1
On 9/25/2021 3:59 PM, Linus Walleij wrote:
> The max VLAN number with non-4K VLAN activated is 15, and the
> range is 0..15. Not 16.
> 
> The impact should be low since we by default have 4K VLAN and
> thus have 4095 VLANs to play with in this switch. There will
> not be a problem unless the code is rewritten to only use
> 16 VLANs.
> 
> Fixes: d8652956cf37 ("net: dsa: realtek-smi: Add Realtek SMI driver")
> Cc: Mauri Sandberg <sandberg@mailfence.com>
> Cc: DENG Qingfang <dqfext@gmail.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
> Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
diff mbox series

Patch

diff --git a/drivers/net/dsa/rtl8366rb.c b/drivers/net/dsa/rtl8366rb.c
index 01d794f94156..6382404814c3 100644
--- a/drivers/net/dsa/rtl8366rb.c
+++ b/drivers/net/dsa/rtl8366rb.c
@@ -1520,7 +1520,7 @@  static int rtl8366rb_set_mc_index(struct realtek_smi *smi, int port, int index)
 
 static bool rtl8366rb_is_vlan_valid(struct realtek_smi *smi, unsigned int vlan)
 {
-	unsigned int max = RTL8366RB_NUM_VLANS;
+	unsigned int max = RTL8366RB_NUM_VLANS - 1;
 
 	if (smi->vlan4k_enabled)
 		max = RTL8366RB_NUM_VIDS - 1;