| Message ID | 20230216104939.3553390-1-alok.a.tiwari@oracle.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: sched: sch: null pointer dereference in htb_offload_move_qdisc() | expand |
On Thu, Feb 16, 2023 at 02:49:40AM -0800, Alok Tiwari wrote: > A possible case of null pointer dereference detected by static analyzer > htb_destroy_class_offload() is calling htb_find() which can return NULL value > for invalid class id, moved_cl=htb_find(classid, sch); > in that case it should not pass 'moved_cl' to htb_offload_move_qdisc() > if 'moved_cl' is NULL pointer return -EINVAL. > > Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com> Conceptually, code looks fine, but it probably won't be accepted without: - imperative verb in the title - tree, to which patch must be applied [0] - more nicely written and formatted commit message. If you are referring to a static analyzer and not to common logic, maybe include, how the warning looks. Separate your text into sentences and paragraphs. [0] https://www.kernel.org/doc/html/v5.3/networking/netdev-FAQ.html#q-how-do-i-indicate-which-tree-net-vs-net-next-my-patch-should-be-in > --- > net/sched/sch_htb.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c > index 92f2975b6a82..5a96d9ea3221 100644 > --- a/net/sched/sch_htb.c > +++ b/net/sched/sch_htb.c > @@ -1601,6 +1601,8 @@ static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl, > u32 classid = TC_H_MAJ(sch->handle) | > TC_H_MIN(offload_opt.classid); > struct htb_class *moved_cl = htb_find(classid, sch); > + if (WARN_ON_ONCE(!moved_cl)) > + return -EINVAL; > > htb_offload_move_qdisc(sch, moved_cl, cl, destroying); > } > -- > 2.39.1 >
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 92f2975b6a82..5a96d9ea3221 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -1601,6 +1601,8 @@ static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl, u32 classid = TC_H_MAJ(sch->handle) | TC_H_MIN(offload_opt.classid); struct htb_class *moved_cl = htb_find(classid, sch); + if (WARN_ON_ONCE(!moved_cl)) + return -EINVAL; htb_offload_move_qdisc(sch, moved_cl, cl, destroying); }
A possible case of null pointer dereference detected by static analyzer htb_destroy_class_offload() is calling htb_find() which can return NULL value for invalid class id, moved_cl=htb_find(classid, sch); in that case it should not pass 'moved_cl' to htb_offload_move_qdisc() if 'moved_cl' is NULL pointer return -EINVAL. Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com> --- net/sched/sch_htb.c | 2 ++ 1 file changed, 2 insertions(+)