syzbot

ext4: Unknown parameter ''
__nla_validate_parse: 24 callbacks suppressed
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'.
==================================================================
BUG: KCSAN: data-race in dd_insert_requests / ll_back_merge_fn

write to 0xffff888102864390 of 8 bytes by task 31035 on cpu 1:
 dd_insert_request block/mq-deadline.c:836 [inline]
 dd_insert_requests+0x4b1/0x670 block/mq-deadline.c:877
 blk_mq_dispatch_plug_list block/blk-mq.c:2761 [inline]
 blk_mq_flush_plug_list+0x67f/0xda0 block/blk-mq.c:2816
 __blk_flush_plug+0x210/0x260 block/blk-core.c:1141
 blk_finish_plug+0x47/0x60 block/blk-core.c:1165
 __iomap_dio_rw+0xc3f/0x10a0 fs/iomap/direct-io.c:583
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:665
 ext4_dio_read_iter fs/ext4/file.c:94 [inline]
 ext4_file_read_iter+0x21c/0x2a0 fs/ext4/file.c:145
 call_read_iter include/linux/fs.h:1871 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:367
 vfs_splice_read fs/splice.c:995 [inline]
 splice_direct_to_actor+0x2aa/0x690 fs/splice.c:1072
 do_splice_direct+0x10d/0x190 fs/splice.c:1197
 do_sendfile+0x3b6/0x9a0 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888102864390 of 8 bytes by task 31029 on cpu 0:
 req_set_nomerge block/blk.h:349 [inline]
 ll_back_merge_fn+0x29c/0x4a0 block/blk-merge.c:647
 bio_attempt_back_merge+0x58/0x500 block/blk-merge.c:982
 blk_attempt_bio_merge+0x43d/0x480 block/blk-merge.c:1068
 blk_attempt_plug_merge+0xb4/0xf0 block/blk-merge.c:1115
 blk_mq_attempt_bio_merge block/blk-mq.c:2857 [inline]
 blk_mq_get_new_requests block/blk-mq.c:2880 [inline]
 blk_mq_submit_bio+0x752/0xd70 block/blk-mq.c:2988
 __submit_bio+0x11c/0x350 block/blk-core.c:598
 __submit_bio_noacct_mq block/blk-core.c:677 [inline]
 submit_bio_noacct_nocheck+0x449/0x5e0 block/blk-core.c:706
 submit_bio_noacct+0x700/0x8a0 block/blk-core.c:800
 submit_bio+0xb7/0xc0 block/blk-core.c:833
 swap_writepage_bdev_async mm/page_io.c:369 [inline]
 __swap_writepage+0x4bf/0xa00 mm/page_io.c:387
 swap_writepage+0x6e/0x120 mm/page_io.c:207
 pageout mm/vmscan.c:1355 [inline]
 shrink_folio_list+0x195e/0x2550 mm/vmscan.c:2015
 shrink_inactive_list mm/vmscan.c:2614 [inline]
 shrink_list mm/vmscan.c:2855 [inline]
 shrink_lruvec+0xd80/0x17a0 mm/vmscan.c:6303
 shrink_node_memcgs mm/vmscan.c:6489 [inline]
 shrink_node+0xab3/0x15c0 mm/vmscan.c:6524
 shrink_zones mm/vmscan.c:6763 [inline]
 do_try_to_free_pages+0x43d/0xce0 mm/vmscan.c:6825
 try_to_free_mem_cgroup_pages+0x1e2/0x480 mm/vmscan.c:7140
 try_charge_memcg+0x280/0xd20 mm/memcontrol.c:2695
 obj_cgroup_charge_pages+0xab/0x130 mm/memcontrol.c:3109
 __memcg_kmem_charge_page+0x1d5/0x2c0 mm/memcontrol.c:3135
 __alloc_pages+0x1bb/0x340 mm/page_alloc.c:4494
 alloc_pages+0x3e1/0x4e0
 vm_area_alloc_pages mm/vmalloc.c:3059 [inline]
 __vmalloc_area_node mm/vmalloc.c:3135 [inline]
 __vmalloc_node_range+0x6d2/0xea0 mm/vmalloc.c:3316
 kvmalloc_node+0x121/0x160 mm/util.c:629
 kvmalloc include/linux/slab.h:720 [inline]
 xt_alloc_table_info+0x3d/0x80 net/netfilter/x_tables.c:1192
 do_replace net/ipv4/netfilter/arp_tables.c:970 [inline]
 do_arpt_set_ctl+0x615/0x1390 net/ipv4/netfilter/arp_tables.c:1421
 nf_setsockopt+0x18d/0x1b0 net/netfilter/nf_sockopt.c:101
 ip_setsockopt+0xe6/0x100 net/ipv4/ip_sockglue.c:1467
 tcp_setsockopt+0x90/0xa0 net/ipv4/tcp.c:3697
 sock_common_setsockopt+0x61/0x70 net/core/sock.c:3697
 __sys_setsockopt+0x1c9/0x230 net/socket.c:2263
 __do_sys_setsockopt net/socket.c:2274 [inline]
 __se_sys_setsockopt net/socket.c:2271 [inline]
 __x64_sys_setsockopt+0x66/0x80 net/socket.c:2271
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000000 -> 0xffff8881031b2300

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31029 Comm: syz-executor.4 Not tainted 6.5.0-rc7-syzkaller-00004-gf7757129e3de #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
==================================================================
syz-executor.4 (31029) used greatest stack depth: 8248 bytes left