KCSAN: data-race in page_cache_sync_ra / read

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in page_cache_sync_ra / read_pages fs mm	6				1	730d	730d	0/29	auto-obsoleted due to no activity on 2024/09/16 03:14
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BUG: KCSAN: data-race in page_cache_sync_ra / read_pages

write to 0xffff88811c4393a4 of 4 bytes by task 5358 on cpu 1:
 page_cache_sync_ra+0x540/0x670
 page_cache_sync_readahead include/linux/pagemap.h:1397 [inline]
 filemap_get_pages+0x2c1/0x10e0 mm/filemap.c:2537
 filemap_read+0x221/0x6a0 mm/filemap.c:2637
 generic_file_read_iter+0x78/0x330 mm/filemap.c:2825
 ext4_file_read_iter+0x1cc/0x290
 copy_splice_read+0x3a0/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 splice_direct_to_actor+0x28b/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x398/0x660 fs/read_write.c:1363
 __do_sys_sendfile64 fs/read_write.c:1424 [inline]
 __se_sys_sendfile64 fs/read_write.c:1410 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1410
 x64_sys_call+0xfbd/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811c4393a4 of 4 bytes by task 5363 on cpu 0:
 read_pages+0x25c/0x540 mm/readahead.c:171
 page_cache_ra_unbounded+0x2b8/0x310 mm/readahead.c:295
 page_cache_sync_ra+0x652/0x670
 page_cache_sync_readahead include/linux/pagemap.h:1397 [inline]
 filemap_get_pages+0x2c1/0x10e0 mm/filemap.c:2537
 filemap_read+0x221/0x6a0 mm/filemap.c:2637
 generic_file_read_iter+0x78/0x330 mm/filemap.c:2825
 ext4_file_read_iter+0x1cc/0x290
 copy_splice_read+0x3a0/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 splice_direct_to_actor+0x28b/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x398/0x660 fs/read_write.c:1363
 __do_sys_sendfile64 fs/read_write.c:1424 [inline]
 __se_sys_sendfile64 fs/read_write.c:1410 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1410
 x64_sys_call+0xfbd/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000002 -> 0x00000010

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 5363 Comm: syz.2.543 Not tainted 6.13.0-rc6-syzkaller-00038-g09a0fa92e5b4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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