mainline inclusion
from mainline-v6.5-rc1
commit 11b73313c12403f617b47752db0ab3deef201af7
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7RC8S
CVE: NA

--------------------------------

In blamed commit, I missed that get_dist_table() was allocating
memory using GFP_KERNEL, and acquiring qdisc lock to perform
the swap of newly allocated table with current one.

In this patch, get_dist_table() is allocating memory and
copy user data before we acquire the qdisc lock.

Then we perform swap operations while being protected by the lock.

Note that after this patch netem_change() no longer can do partial changes.
If an error is returned, qdisc conf is left unchanged.

Fixes: 2174a08d ("sch_netem: acquire qdisc lock in netem_change()")
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: NSimon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230622181503.2327695-1-edumazet@google.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>