| Message ID | 20200928153219.285343-1-3chas3@gmail.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Thomas Monjalon |
| Headers | show |
| Series | net: check that seg is valid before dereference | expand |
| Context | Check | Description |
|---|---|---|
| ci/iol-mellanox-Performance | success | Performance Testing PASS |
| ci/travis-robot | success | Travis build: passed |
| ci/iol-intel-Performance | success | Performance Testing PASS |
| ci/Intel-compilation | success | Compilation OK |
| ci/iol-testing | success | Testing PASS |
| ci/iol-broadcom-Performance | success | Performance Testing PASS |
| ci/iol-intel-Functional | success | Functional Testing PASS |
| ci/iol-broadcom-Functional | success | Functional Testing PASS |
| ci/checkpatch | success | coding style OK |
> -----Original Message----- > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Chas Williams > Sent: Monday, September 28, 2020 11:32 PM > To: dev@dpdk.org > Cc: olivier.matz@6wind.com; Chas Williams <3chas3@gmail.com> > Subject: [dpdk-dev] [PATCH] net: check that seg is valid before dereference > > If the overall pkt_len and segment lengths are out of agreement, it is possible > for the seg to be NULL after the loop. Add assert to check this condition in > debug builds. > > Fixes: c442fed81bb9 ("net: add function to calculate checksum in mbuf") > > Signed-off-by: Chas Williams <3chas3@gmail.com> > --- > lib/librte_net/rte_ip.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h index > fcd1eb342..6b3e4cdda 100644 > --- a/lib/librte_net/rte_ip.h > +++ b/lib/librte_net/rte_ip.h > @@ -225,6 +225,7 @@ rte_raw_cksum_mbuf(const struct rte_mbuf *m, > uint32_t off, uint32_t len, > break; > off -= seglen; > } > + RTE_ASSERT(seg != NULL); Is it better to return an error code? > seglen -= off; > buf = rte_pktmbuf_mtod_offset(seg, const char *, off); > if (seglen >= len) { > -- > 2.26.2
On 9/28/20 11:01 PM, wangyunjian wrote: >> -----Original Message----- >> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Chas Williams >> Sent: Monday, September 28, 2020 11:32 PM >> To: dev@dpdk.org >> Cc: olivier.matz@6wind.com; Chas Williams <3chas3@gmail.com> >> Subject: [dpdk-dev] [PATCH] net: check that seg is valid before dereference >> >> If the overall pkt_len and segment lengths are out of agreement, it is possible >> for the seg to be NULL after the loop. Add assert to check this condition in >> debug builds. >> >> Fixes: c442fed81bb9 ("net: add function to calculate checksum in mbuf") >> >> Signed-off-by: Chas Williams <3chas3@gmail.com> >> --- >> lib/librte_net/rte_ip.h | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h index >> fcd1eb342..6b3e4cdda 100644 >> --- a/lib/librte_net/rte_ip.h >> +++ b/lib/librte_net/rte_ip.h >> @@ -225,6 +225,7 @@ rte_raw_cksum_mbuf(const struct rte_mbuf *m, >> uint32_t off, uint32_t len, >> break; >> off -= seglen; >> } >> + RTE_ASSERT(seg != NULL); > > Is it better to return an error code? Maybe. However, to get into this state your mbuf chain is already badly broken. Personally, I would prefer an immediate failure in the application so I can track down the source of this error. No one is checking the return code now, so returning one wouldn't really help unless I also fix the callers. Lastly, would everyone be happy with an extra branch in the virtio RX path? > >> seglen -= off; >> buf = rte_pktmbuf_mtod_offset(seg, const char *, off); >> if (seglen >= len) { >> -- >> 2.26.2 >
diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h index fcd1eb342..6b3e4cdda 100644 --- a/lib/librte_net/rte_ip.h +++ b/lib/librte_net/rte_ip.h @@ -225,6 +225,7 @@ rte_raw_cksum_mbuf(const struct rte_mbuf *m, uint32_t off, uint32_t len, break; off -= seglen; } + RTE_ASSERT(seg != NULL); seglen -= off; buf = rte_pktmbuf_mtod_offset(seg, const char *, off); if (seglen >= len) {
If the overall pkt_len and segment lengths are out of agreement, it is possible for the seg to be NULL after the loop. Add assert to check this condition in debug builds. Fixes: c442fed81bb9 ("net: add function to calculate checksum in mbuf") Signed-off-by: Chas Williams <3chas3@gmail.com> --- lib/librte_net/rte_ip.h | 1 + 1 file changed, 1 insertion(+)