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author王贇 <yun.wang@linux.alibaba.com>2021-09-24 05:35:58 +0300
committerDavid S. Miller <davem@davemloft.net>2021-09-26 13:09:07 +0300
commitb193e15ac69d56f35e1d8e2b5d16cbd47764d053 (patch)
tree6a5e9c6f1cef6e942f20060db4b193ed3006a0d0 /net
parent7fe7f3182a0dd8f9bad463598ed103b3d8cfa739 (diff)
downloadlinux-b193e15ac69d56f35e1d8e2b5d16cbd47764d053.tar.xz
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>
Diffstat (limited to 'net')
-rw-r--r--net/sched/sch_api.c6
1 files changed, 6 insertions, 0 deletions
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);