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BUG: KCSAN: data-race in __folio_activate / skb_append_pagefrags

write to 0xffffea0004c315c8 of 8 bytes by task 17008 on cpu 0:
 list_del include/linux/list.h:149 [inline]
 lruvec_del_folio include/linux/mm_inline.h:137 [inline]
 __folio_activate+0x218/0x760 mm/swap.c:315
 __activate_page+0x45/0xf0 mm/swap.c:329
 pagevec_lru_move_fn+0x230/0x500 mm/swap.c:207
 activate_page_drain mm/swap.c:337 [inline]
 lru_add_drain_cpu+0x230/0x260 mm/swap.c:626
 lru_add_drain+0x21/0x60 mm/swap.c:706
 __pagevec_release+0x3a/0x70 mm/swap.c:997
 pagevec_release include/linux/pagevec.h:82 [inline]
 folio_batch_release include/linux/pagevec.h:146 [inline]
 invalidate_inode_pages2_range+0x5cf/0x670 mm/truncate.c:690
 __iomap_dio_rw+0x5f9/0xf50 fs/iomap/direct-io.c:582
 iomap_dio_rw+0x3c/0x80 fs/iomap/direct-io.c:689
 ext4_dio_write_iter fs/ext4/file.c:566 [inline]
 ext4_file_write_iter+0xaa9/0x1210 fs/ext4/file.c:677
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:868
 vfs_iter_write+0x4c/0x70 fs/read_write.c:909
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x660 fs/splice.c:891
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1262
 __do_sys_sendfile64 fs/read_write.c:1327 [inline]
 __se_sys_sendfile64 fs/read_write.c:1313 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1313
 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+0x46/0xb0

read to 0xffffea0004c315c8 of 8 bytes by task 17011 on cpu 1:
 page_is_pfmemalloc include/linux/mm.h:1794 [inline]
 __skb_fill_page_desc include/linux/skbuff.h:2559 [inline]
 skb_fill_page_desc include/linux/skbuff.h:2580 [inline]
 skb_append_pagefrags+0x1e9/0x440 net/core/skbuff.c:3841
 unix_stream_sendpage+0x45e/0x990 net/unix/af_unix.c:2290
 kernel_sendpage+0x184/0x300 net/socket.c:3571
 sock_sendpage+0x5a/0x70 net/socket.c:1054
 pipe_to_sendpage+0x128/0x160 fs/splice.c:364
 splice_from_pipe_feed fs/splice.c:418 [inline]
 __splice_from_pipe+0x222/0x4d0 fs/splice.c:562
 splice_from_pipe fs/splice.c:597 [inline]
 generic_splice_sendpage+0x89/0xc0 fs/splice.c:746
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x660 fs/splice.c:891
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1262
 __do_sys_sendfile64 fs/read_write.c:1327 [inline]
 __se_sys_sendfile64 fs/read_write.c:1313 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1313
 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+0x46/0xb0

value changed: 0xffffea000467f888 -> 0xffffea0004702d08

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17011 Comm: syz-executor.3 Not tainted 5.19.0-rc1-syzkaller-00262-g0885eacdc81f-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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