| Message ID | 20231107123600.14529-1-shum.sdl@nppct.ru (mailing list archive) |
|---|---|
| State | Rejected |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | iphase: Adding a null pointer check | expand |
On Tue, 7 Nov 2023 15:36:00 +0300 Andrey Shumilin wrote: > The pointer <dev->desc_tbl[i].iavcc> is dereferenced on line 195. > Further in the code, it is checked for null on line 204. > It is proposed to add a check before dereferencing the pointer. How do you know this is the right way to address the problem. Much easier to debug a crash than misbehaving driver. This is ancient code, leave it be.
Proposal for subject: atm: iphase: Move check for NULL before derefence in get_desc() On 07.11.2023 15:36, Andrey Shumilin wrote: > The pointer <dev->desc_tbl[i].iavcc> is dereferenced on line 195. > Further in the code, it is checked for null on line 204. > It is proposed to add a check before dereferencing the pointer. Line numbers in commit messages are not welcome since they are subject for change and a reader of the message likely has other code at that lines in his version of the file. > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > Signed-off-by: Andrey Shumilin <shum.sdl@nppct.ru> > --- > drivers/atm/iphase.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/atm/iphase.c b/drivers/atm/iphase.c > index 324148686953..596422fbfacc 100644 > --- a/drivers/atm/iphase.c > +++ b/drivers/atm/iphase.c > @@ -192,6 +192,11 @@ static u16 get_desc (IADEV *dev, struct ia_vcc *iavcc) { > i++; > continue; > } > + if (!(iavcc_r = dev->desc_tbl[i].iavcc)) { > + printk("Fatal err, desc table vcc or skb is NULL\n"); > + i++; > + continue; > + } Error message should be fixed, skb is not check for NULL here. > ltimeout = dev->desc_tbl[i].iavcc->ltimeout; > delta = jiffies - dev->desc_tbl[i].timestamp; > if (delta >= ltimeout) { > > if (!dev->desc_tbl[i].txskb || !(iavcc_r = dev->desc_tbl[i].iavcc)) > printk("Fatal err, desc table vcc or skb is NULL\n"); The existing check should be fixed to check for skb only. -- Alexey
diff --git a/drivers/atm/iphase.c b/drivers/atm/iphase.c index 324148686953..596422fbfacc 100644 --- a/drivers/atm/iphase.c +++ b/drivers/atm/iphase.c @@ -192,6 +192,11 @@ static u16 get_desc (IADEV *dev, struct ia_vcc *iavcc) { i++; continue; } + if (!(iavcc_r = dev->desc_tbl[i].iavcc)) { + printk("Fatal err, desc table vcc or skb is NULL\n"); + i++; + continue; + } ltimeout = dev->desc_tbl[i].iavcc->ltimeout; delta = jiffies - dev->desc_tbl[i].timestamp; if (delta >= ltimeout) {
The pointer <dev->desc_tbl[i].iavcc> is dereferenced on line 195. Further in the code, it is checked for null on line 204. It is proposed to add a check before dereferencing the pointer. Found by Linux Verification Center (linuxtesting.org) with SVACE. Signed-off-by: Andrey Shumilin <shum.sdl@nppct.ru> --- drivers/atm/iphase.c | 5 +++++ 1 file changed, 5 insertions(+)