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Stanislav Fomichev 0a13c1e0a4 net: revert to lockless TC_SETUP_BLOCK and TC_SETUP_FT
There is a couple of places from which we can arrive to ndo_setup_tc
with TC_SETUP_BLOCK/TC_SETUP_FT:
- netlink
- netlink notifier
- netdev notifier

Locking netdev too deep in this call chain seems to be problematic
(especially assuming some/all of the call_netdevice_notifiers
NETDEV_UNREGISTER) might soon be running with the instance lock).
Revert to lockless ndo_setup_tc for TC_SETUP_BLOCK/TC_SETUP_FT. NFT
framework already takes care of most of the locking. Document
the assumptions.

ndo_setup_tc TC_SETUP_BLOCK
  nft_block_offload_cmd
    nft_chain_offload_cmd
      nft_flow_block_chain
        nft_flow_offload_chain
	  nft_flow_rule_offload_abort
	    nft_flow_rule_offload_commit
	  nft_flow_rule_offload_commit
	    nf_tables_commit
	      nfnetlink_rcv_batch
	        nfnetlink_rcv_skb_batch
		  nfnetlink_rcv
	nft_offload_netdev_event
	  NETDEV_UNREGISTER notifier

ndo_setup_tc TC_SETUP_FT
  nf_flow_table_offload_cmd
    nf_flow_table_offload_setup
      nft_unregister_flowtable_hook
        nft_register_flowtable_net_hooks
	  nft_flowtable_update
	  nf_tables_newflowtable
	    nfnetlink_rcv_batch (.call NFNL_CB_BATCH)
	nft_flowtable_update
	  nf_tables_newflowtable
	nft_flowtable_event
	  nf_tables_flowtable_event
	    NETDEV_UNREGISTER notifier
      __nft_unregister_flowtable_net_hooks
        nft_unregister_flowtable_net_hooks
	  nf_tables_commit
	    nfnetlink_rcv_batch (.call NFNL_CB_BATCH)
	  __nf_tables_abort
	    nf_tables_abort
	      nfnetlink_rcv_batch
	__nft_release_hook
	  __nft_release_hooks
	    nf_tables_pre_exit_net -> module unload
	  nft_rcv_nl_event
	    netlink_register_notifier (oh boy)
      nft_register_flowtable_net_hooks
      	nft_flowtable_update
	  nf_tables_newflowtable
        nf_tables_newflowtable

Fixes: c4f0f30b42 ("net: hold netdev instance lock during nft ndo_setup_tc")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Reported-by: syzbot+0afb4bcf91e5a1afdcad@syzkaller.appspotmail.com
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250308044726.1193222-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-12 13:02:00 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-03-06 13:03:35 -08:00
block block-6.14-20250228 2025-02-28 09:43:46 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
Documentation net: revert to lockless TC_SETUP_BLOCK and TC_SETUP_FT 2025-03-12 13:02:00 -07:00
drivers net: ti: icssg-prueth: Add XDP support 2025-03-11 11:09:56 +01:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-03-06 13:03:35 -08:00
include net: revert to lockless TC_SETUP_BLOCK and TC_SETUP_FT 2025-03-12 13:02:00 -07:00
init Kbuild updates for v6.14 2025-01-31 12:07:07 -08:00
io_uring Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-03-06 13:03:35 -08:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel net: move misc netdev_lock flavors to a separate header 2025-03-08 09:06:50 -08:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-03-06 13:03:35 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm arm64 fixes for -rc5 2025-03-01 13:44:51 -08:00
net net: revert to lockless TC_SETUP_BLOCK and TC_SETUP_FT 2025-03-12 13:02:00 -07:00
rust Driver core api addition for 6.14-rc3 2025-02-16 12:54:42 -08:00
samples Driver core api addition for 6.14-rc3 2025-02-16 12:54:42 -08:00
scripts coccinelle: Add missing (GE)NL_SET_ERR_MSG_* to strings ending with newline test 2025-02-27 18:11:37 -08:00
security Landlock fix for v6.14-rc5 2025-02-26 11:55:44 -08:00
sound ASoC: Fixes for v6.14 2025-02-26 15:00:25 +01:00
tools selftests/net: expand cmsg_ip with MSG_MORE 2025-03-10 13:13:04 -07:00
usr kbuild: Drop support for include/asm-<arch> in headers_check.pl 2024-12-21 11:43:17 +09:00
virt KVM: remove kvm_arch_post_init_vm 2025-02-04 11:27:45 -05:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: use host dylib naming convention to support macOS 2025-01-10 01:01:24 +01:00
.mailmap We have been notified of a TLS regression that will be addressed 2025-03-06 09:34:54 -10:00
.rustfmt.toml
COPYING
CREDITS MAINTAINERS: Move Pavel to kernel.org address 2025-02-07 09:12:33 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS MAINTAINERS: adjust entry in AIROHA ETHERNET DRIVER 2025-03-07 19:41:52 -08:00
Makefile Linux 6.14-rc5 2025-03-02 11:48:20 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.