diff options
| author | 王贇 <yun.wang@linux.alibaba.com> | 2021-09-24 10:35:58 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-09-26 11:09:07 +0100 |
| commit | b193e15ac69d56f35e1d8e2b5d16cbd47764d053 (patch) | |
| tree | 6a5e9c6f1cef6e942f20060db4b193ed3006a0d0 | |
| parent | 7fe7f3182a0dd8f9bad463598ed103b3d8cfa739 (diff) | |
net: prevent user from passing illegal stab size
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>
| -rw-r--r-- | include/net/pkt_sched.h | 1 | ||||
| -rw-r--r-- | net/sched/sch_api.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h index 6d7b12cba015..bf79f3a890af 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 5e90e9b160e3..12f39a2dffd4 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -513,6 +513,12 @@ 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); |