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KCSAN: data-race in delete_from_page_cache_batch / filemap_write_and_wait_range (2)

Status: moderation: reported on 2025/07/17 06:31
Subsystems: block
[Documentation on labels]
Reported-by: syzbot+0df30ca8c4eaf06a93ae@syzkaller.appspotmail.com
First crash: 6h26m, last: 6h26m
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in delete_from_page_cache_batch / filemap_write_and_wait_range ext4 6 1 1570d 1570d 0/29 auto-closed as invalid on 2021/05/17 11:06

Sample crash report:
==================================================================
BUG: KCSAN: data-race in delete_from_page_cache_batch / filemap_write_and_wait_range

read-write to 0xffff8881005f0bb0 of 8 bytes by task 12189 on cpu 0:
 page_cache_delete_batch mm/filemap.c:313 [inline]
 delete_from_page_cache_batch+0x4f1/0x6f0 mm/filemap.c:332
 truncate_inode_pages_range+0x1b8/0x690 mm/truncate.c:380
 truncate_inode_pages+0x24/0x30 mm/truncate.c:460
 kill_bdev block/bdev.c:91 [inline]
 set_blocksize+0x259/0x310 block/bdev.c:207
 sb_set_blocksize block/bdev.c:224 [inline]
 sb_min_blocksize+0xb8/0x140 block/bdev.c:239
 fat_fill_super+0x33b/0x1ce0 fs/fat/inode.c:1597
 vfat_fill_super+0x24/0x30 fs/fat/namei_vfat.c:1197
 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1681
 get_tree_bdev+0x1f/0x30 fs/super.c:1704
 vfat_get_tree+0x1c/0x30 fs/fat/namei_vfat.c:1202
 vfs_get_tree+0x57/0x1d0 fs/super.c:1804
 do_new_mount+0x207/0x680 fs/namespace.c:3902
 path_mount+0x4a4/0xb20 fs/namespace.c:4226
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4427
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4427
 x64_sys_call+0xd36/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881005f0bb0 of 8 bytes by task 3645 on cpu 1:
 mapping_needs_writeback mm/filemap.c:641 [inline]
 filemap_write_and_wait_range+0x59/0x340 mm/filemap.c:690
 filemap_write_and_wait include/linux/pagemap.h:68 [inline]
 sync_blockdev block/bdev.c:260 [inline]
 bdev_release+0xeb/0x3d0 block/bdev.c:1126
 blkdev_release+0x15/0x20 block/fops.c:684
 __fput+0x29b/0x650 fs/file_table.c:465
 fput_close_sync+0x6e/0x120 fs/file_table.c:570
 __do_sys_close fs/open.c:1589 [inline]
 __se_sys_close fs/open.c:1574 [inline]
 __x64_sys_close+0x56/0xf0 fs/open.c:1574
 x64_sys_call+0x2747/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000001 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3645 Comm: udevd Not tainted 6.16.0-rc6-syzkaller-00037-ge2291551827f #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/17 06:31 upstream e2291551827f 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in delete_from_page_cache_batch / filemap_write_and_wait_range
* Struck through repros no longer work on HEAD.