335178d542
syzbot reported following crash:
list_del corruption, ffff88808c9bb000->prev is LIST_POISON2 (dead000000000122)
[..]
Call Trace:
__list_del_entry include/linux/list.h:131 [inline]
list_del_rcu include/linux/rculist.h:148 [inline]
nf_tables_commit+0x1068/0x3b30 net/netfilter/nf_tables_api.c:7183
[..]
The commit transaction list has:
NFT_MSG_NEWTABLE
NFT_MSG_NEWFLOWTABLE
NFT_MSG_DELFLOWTABLE
NFT_MSG_DELTABLE
A missing generation check during DELTABLE processing causes it to queue
the DELFLOWTABLE operation a second time, so we corrupt the list here:
case NFT_MSG_DELFLOWTABLE:
list_del_rcu(&nft_trans_flowtable(trans)->list);
nf_tables_flowtable_notify(&trans->ctx,
because we have two different DELFLOWTABLE transactions for the same
flowtable. We then call list_del_rcu() twice for the same flowtable->list.
The object handling seems to suffer from the same bug so add a generation
check too and only queue delete transactions for flowtables/objects that
are still active in the next generation.
Reported-by: syzbot+37a6804945a3a13b1572@syzkaller.appspotmail.com
Fixes: 3b49e2e94e6eb ("netfilter: nf_tables: add flow table netlink frontend")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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.