linux/net/core
Eric Dumazet 228ebc41df net: do not sense pfmemalloc status in skb_append_pagefrags()
skb_append_pagefrags() is used by af_unix and udp sendpage()
implementation so far.

In commit 3261400639 ("tcp: TX zerocopy should not sense
pfmemalloc status") we explained why we should not sense
pfmemalloc status for pages owned by user space.

We should also use skb_fill_page_desc_noacc()
in skb_append_pagefrags() to avoid following KCSAN report:

BUG: KCSAN: data-race in lru_add_fn / skb_append_pagefrags

write to 0xffffea00058fc1c8 of 8 bytes by task 17319 on cpu 0:
__list_add include/linux/list.h:73 [inline]
list_add include/linux/list.h:88 [inline]
lruvec_add_folio include/linux/mm_inline.h:323 [inline]
lru_add_fn+0x327/0x410 mm/swap.c:228
folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246
lru_add_drain_cpu+0x73/0x250 mm/swap.c:669
lru_add_drain+0x21/0x60 mm/swap.c:773
free_pages_and_swap_cache+0x16/0x70 mm/swap_state.c:311
tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:256 [inline]
tlb_flush_mmu+0x5b2/0x640 mm/mmu_gather.c:263
tlb_finish_mmu+0x86/0x100 mm/mmu_gather.c:363
exit_mmap+0x190/0x4d0 mm/mmap.c:3098
__mmput+0x27/0x1b0 kernel/fork.c:1185
mmput+0x3d/0x50 kernel/fork.c:1207
copy_process+0x19fc/0x2100 kernel/fork.c:2518
kernel_clone+0x166/0x550 kernel/fork.c:2671
__do_sys_clone kernel/fork.c:2812 [inline]
__se_sys_clone kernel/fork.c:2796 [inline]
__x64_sys_clone+0xc3/0xf0 kernel/fork.c:2796
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffffea00058fc1c8 of 8 bytes by task 17325 on cpu 1:
page_is_pfmemalloc include/linux/mm.h:1817 [inline]
__skb_fill_page_desc include/linux/skbuff.h:2432 [inline]
skb_fill_page_desc include/linux/skbuff.h:2453 [inline]
skb_append_pagefrags+0x210/0x600 net/core/skbuff.c:3974
unix_stream_sendpage+0x45e/0x990 net/unix/af_unix.c:2338
kernel_sendpage+0x184/0x300 net/socket.c:3561
sock_sendpage+0x5a/0x70 net/socket.c:1054
pipe_to_sendpage+0x128/0x160 fs/splice.c:361
splice_from_pipe_feed fs/splice.c:415 [inline]
__splice_from_pipe+0x222/0x4d0 fs/splice.c:559
splice_from_pipe fs/splice.c:594 [inline]
generic_splice_sendpage+0x89/0xc0 fs/splice.c:743
do_splice_from fs/splice.c:764 [inline]
direct_splice_actor+0x80/0xa0 fs/splice.c:931
splice_direct_to_actor+0x305/0x620 fs/splice.c:886
do_splice_direct+0xfb/0x180 fs/splice.c:974
do_sendfile+0x3bf/0x910 fs/read_write.c:1255
__do_sys_sendfile64 fs/read_write.c:1323 [inline]
__se_sys_sendfile64 fs/read_write.c:1309 [inline]
__x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000000 -> 0xffffea00058fc188

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17325 Comm: syz-executor.0 Not tainted 6.1.0-rc1-syzkaller-00158-g440b7895c990-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022

Fixes: 3261400639 ("tcp: TX zerocopy should not sense pfmemalloc status")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221027040346.1104204-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-27 11:25:13 -07:00
..
bpf_sk_storage.c net: Fix data-races around sysctl_optmem_max. 2022-08-24 13:46:57 +01:00
datagram.c tcp: TX zerocopy should not sense pfmemalloc status 2022-09-02 12:29:02 +01:00
dev_addr_lists_test.c net: kunit: add a test for dev_addr_lists 2021-11-20 12:25:57 +00:00
dev_addr_lists.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
dev_ioctl.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
dev.c net: Fix return value of qdisc ingress handling on success 2022-10-19 14:04:36 +01:00
dev.h net: add skb_defer_max sysctl 2022-05-16 11:33:59 +01:00
devlink.c net: devlink: add port_init/fini() helpers to allow pre-register/post-unregister functions 2022-09-30 18:17:16 -07:00
drop_monitor.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
dst_cache.c wireguard: device: reset peer src endpoint when netns exits 2021-11-29 19:50:45 -08:00
dst.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
failover.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
fib_notifier.c
fib_rules.c fib: expand fib_rule_policy 2021-12-16 07:18:35 -08:00
filter.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-10-03 13:02:49 -07:00
flow_dissector.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-22 13:02:10 -07:00
flow_offload.c flow_offload: Introduce flow_match_l2tpv3 2022-09-20 09:13:38 +02:00
gen_estimator.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
gen_stats.c net: sched: fix misuse of qcpu->backlog in gnet_stats_add_queue_cpu 2022-08-16 19:38:20 -07:00
gro_cells.c net: drop the weight argument from netif_napi_add 2022-09-28 18:57:14 -07:00
gro.c gro: add support of (hw)gro packets to gro stack 2022-10-03 12:38:34 +01:00
hwbm.c
link_watch.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
lwt_bpf.c bpf, lwt: Fix crash when using bpf_skb_set_tunnel_key() from bpf_xmit lwt hook 2022-04-22 17:45:25 +02:00
lwtunnel.c xfrm: lwtunnel: add lwtunnel support for xfrm interfaces in collect_md mode 2022-08-29 10:44:08 +02:00
Makefile net: skb: export skb drop reaons to user by TRACE_DEFINE_ENUM 2022-09-07 15:28:08 +01:00
neighbour.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
net_namespace.c net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed 2022-10-24 12:40:06 +01:00
net-procfs.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
net-sysfs.c net-sysfs: Convert to use sysfs_emit() APIs 2022-09-30 12:27:44 +01:00
net-sysfs.h
net-traces.c tcp: add tracepoint for checksum errors 2021-05-14 15:26:03 -07:00
netclassid_cgroup.c core: Variable type completion 2022-08-31 09:40:34 +01:00
netevent.c net: core: Correct function name netevent_unregister_notifier() in the kerneldoc 2021-03-28 17:56:56 -07:00
netpoll.c net: move from strlcpy with unused retval to strscpy 2022-08-22 18:06:18 -07:00
netprio_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
of_net.c Revert "of: net: support NVMEM cells with MAC in text format" 2022-01-12 14:14:36 +00:00
page_pool.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
pktgen.c treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
ptp_classifier.c ptp: Add generic PTP is_sync() function 2022-03-07 11:31:34 +00:00
request_sock.c
rtnetlink.c net: rtnetlink: Enslave device before bringing it up 2022-09-20 08:37:44 -07:00
scm.c memcg: enable accounting for scm_fp_list objects 2021-07-20 06:00:38 -07:00
secure_seq.c tcp: Fix data-races around sysctl knobs related to SYN option. 2022-07-20 10:14:49 +01:00
selftests.c net: core: constify mac addrs in selftests 2021-10-24 13:59:44 +01:00
skbuff.c net: do not sense pfmemalloc status in skb_append_pagefrags() 2022-10-27 11:25:13 -07:00
skmsg.c skmsg: pass gfp argument to alloc_sk_msg() 2022-10-16 20:57:17 +01:00
sock_destructor.h skb_expand_head() adjust skb->truesize incorrectly 2021-10-22 12:35:51 -07:00
sock_diag.c net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
sock_map.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-08-17 20:29:36 -07:00
sock_reuseport.c udp: Update reuse->has_conns under reuseport_lock. 2022-10-18 10:17:18 +02:00
sock.c ipv6: Fix data races around sk->sk_prot. 2022-10-12 17:50:37 -07:00
stream.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
sysctl_net_core.c net: sysctl: remove unused variable long_max 2022-09-07 15:31:19 +01:00
timestamping.c
tso.c
utils.c net: core: Use csum_replace_by_diff() and csum_sub() instead of opencoding 2022-02-21 11:40:44 +00:00
xdp.c xdp: improve page_pool xdp_return performance 2022-09-26 11:28:19 -07:00