c7c5e6ff53
syzbot found that forcing a big quantum attribute would crash hosts fast,
essentially using this:
tc qd replace dev eth0 root fq_codel quantum 4294967295
This is because fq_codel_dequeue() would have to loop
~2^31 times in :
if (flow->deficit <= 0) {
flow->deficit += q->quantum;
list_move_tail(&flow->flowchain, &q->old_flows);
goto begin;
}
SFQ max quantum is 2^19 (half a megabyte)
Lets adopt a max quantum of one megabyte for FQ_CODEL.
Fixes: 4b549a2ef4 ("fq_codel: Fair Queue Codel AQM")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.