Messages in this thread | | | Date | Thu, 1 Dec 2022 00:01:11 +0200 | From | Vladimir Oltean <> | Subject | Re: [PATCH] net: dsa: fix NULL pointer dereference in seq_match() |
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On Wed, Nov 30, 2022 at 11:44:31AM +0300, Yuri Karpov wrote: > ptp_parse_header() result is not checked in seq_match() that can lead > to NULL pointer dereferense. > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > Fixes: c6fe0ad2c349 ("net: dsa: mv88e6xxx: add rx/tx timestamping support") > Signed-off-by: Yuri Karpov <YKarpov@ispras.ru> > --- > drivers/net/dsa/mv88e6xxx/hwtstamp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/dsa/mv88e6xxx/hwtstamp.c b/drivers/net/dsa/mv88e6xxx/hwtstamp.c > index 331b4ca089ff..97f30795a2bb 100644 > --- a/drivers/net/dsa/mv88e6xxx/hwtstamp.c > +++ b/drivers/net/dsa/mv88e6xxx/hwtstamp.c > @@ -246,7 +246,7 @@ static int seq_match(struct sk_buff *skb, u16 ts_seqid) > > hdr = ptp_parse_header(skb, type); > > - return ts_seqid == ntohs(hdr->sequence_id); > + return hdr ? ts_seqid == ntohs(hdr->sequence_id) : 0;
NACK.
ptp_parse_header() will never return NULL when called from seq_match(). The skb comes from mv88e6xxx_get_rxts(), which takes it from ps->rx_queue. It was put there by mv88e6xxx_port_rxtstamp(), which prior to that, had a check for ptp_parse_header() returning NULL in mv88e6xxx_should_tstamp().
Please don't just blindly trust your tools.
> } > > static void mv88e6xxx_get_rxts(struct mv88e6xxx_chip *chip, > -- > 2.34.1 >
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