mainlining shenanigans
modprobe calls from the nf_logger_find_get() API causes deadlock in very special cases because they occur with the nf_tables transaction mutex held. In the specific case of nf_log, deadlock is via: A nf_tables -> transaction mutex -> nft_log -> modprobe -> nf_log_syslog \ -> pernet_ops rwsem -> wait for C B netlink event -> rtnl_mutex -> nf_tables transaction mutex -> wait for A C close() -> ip6mr_sk_done -> rtnl_mutex -> wait for B Earlier patch added NFLOG/xt_LOG module softdeps to avoid the need to load the backend module during a transaction. For nft_log we would have to add a softdep for both nfnetlink_log or nf_log_syslog, since we do not know in advance which of the two backends are going to be configured. This defers the modprobe op until after the transaction mutex is released. Tested-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> |
||
---|---|---|
arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
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.