From: 王贇 <yun.wang@linux.alibaba.com> stable inclusion from linux-4.19.212 commit 65492b05f4a4a18300863f00c51481cd8b32c689 -------------------------------- [ Upstream commit b193e15ac69d56f35e1d8e2b5d16cbd47764d053 ] We observed below report when playing with netlink sock: UBSAN: shift-out-of-bounds in net/sched/sch_api.c:580:10 shift exponent 249 is too large for 32-bit type CPU: 0 PID: 685 Comm: a.out Not tainted Call Trace: dump_stack_lvl+0x8d/0xcf ubsan_epilogue+0xa/0x4e __ubsan_handle_shift_out_of_bounds+0x161/0x182 __qdisc_calculate_pkt_len+0xf0/0x190 __dev_queue_xmit+0x2ed/0x15b0 it seems like kernel won't check the stab log value passing from user, and will use the insane value later to calculate pkt_len. This patch just add a check on the size/cell_log to avoid insane calculation. Reported-by: Abaci <abaci@linux.alibaba.com> Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Acked-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- include/net/pkt_sched.h | 1 + net/sched/sch_api.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h index 5e99771a5dcc2..edca90ef3bdc4 100644 --- a/include/net/pkt_sched.h +++ b/include/net/pkt_sched.h @@ -11,6 +11,7 @@ #include <uapi/linux/pkt_sched.h> #define DEFAULT_TX_QUEUE_LEN 1000 +#define STAB_SIZE_LOG_MAX 30 struct qdisc_walker { int stop; diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 576f70e078bc6..2c9aa550763dd 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -498,6 +498,12 @@ static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt, return stab; } + if (s->size_log > STAB_SIZE_LOG_MAX || + s->cell_log > STAB_SIZE_LOG_MAX) { + NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table"); + return ERR_PTR(-EINVAL); + } + stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL); if (!stab) return ERR_PTR(-ENOMEM); -- 2.25.1