KCSAN: data-race in __percpu_counter_limited_add / percpu_counter_add

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __percpu_counter_limited_add / percpu_counter_add_batch (2) mm				1	24d	24d	0/28	moderation: reported on 2024/10/28 03:58
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BUG: KCSAN: data-race in __percpu_counter_limited_add / percpu_counter_add_batch

read-write to 0xffff888100139b50 of 8 bytes by task 11055 on cpu 1:
 percpu_counter_add_batch+0xc9/0x140 lib/percpu_counter.c:96
 percpu_counter_add include/linux/percpu_counter.h:71 [inline]
 percpu_counter_sub include/linux/percpu_counter.h:277 [inline]
 shmem_inode_unacct_blocks mm/shmem.c:251 [inline]
 shmem_recalc_inode+0x130/0x1b0 mm/shmem.c:442
 shmem_undo_range+0xa04/0xa40 mm/shmem.c:1108
 shmem_truncate_range+0x27/0x70 mm/shmem.c:1113
 shmem_setattr+0x792/0x830 mm/shmem.c:1196
 notify_change+0x866/0x8e0 fs/attr.c:499
 do_truncate+0x116/0x150 fs/open.c:66
 handle_truncate fs/namei.c:3280 [inline]
 do_open fs/namei.c:3626 [inline]
 path_openat+0x19b6/0x1d70 fs/namei.c:3779
 do_filp_open+0xf6/0x200 fs/namei.c:3809
 do_sys_openat2+0xab/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888100139b50 of 8 bytes by task 11039 on cpu 0:
 __percpu_counter_limited_add+0xfa/0x460
 percpu_counter_limited_add include/linux/percpu_counter.h:77 [inline]
 shmem_inode_acct_blocks+0xf4/0x230 mm/shmem.c:220
 shmem_alloc_and_add_folio mm/shmem.c:1695 [inline]
 shmem_get_folio_gfp+0x59f/0xb40 mm/shmem.c:2054
 shmem_get_folio mm/shmem.c:2136 [inline]
 shmem_write_begin+0xa0/0x1b0 mm/shmem.c:2719
 generic_perform_write+0x1c9/0x410 mm/filemap.c:3918
 shmem_file_write_iter+0xc8/0xe0 mm/shmem.c:2895
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x48a/0x790 fs/read_write.c:584
 ksys_write+0xeb/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000015ced -> 0x0000000000011cf0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11039 Comm: syz-executor.5 Not tainted 6.7.0-rc6-syzkaller-00010-g2cf4f94d8e86 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
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