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KCSAN: data-race in filemap_fault / generic_write_end (10)

Status: auto-obsoleted due to no activity on 2023/12/25 00:01
Subsystems: exfat
[Documentation on labels]
Reported-by: syzbot+a4e28512dee4c8b02065@syzkaller.appspotmail.com
First crash: 132d, last: 120d
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in filemap_fault / generic_write_end (3) ext4 2 1261d 1262d 0/26 auto-closed as invalid on 2020/10/24 13:06
upstream KCSAN: data-race in filemap_fault / generic_write_end (8) ext4 2 405d 408d 0/26 auto-obsoleted due to no activity on 2023/03/17 09:30
upstream KCSAN: data-race in filemap_fault / generic_write_end (9) ext4 3 300d 302d 0/26 auto-obsoleted due to no activity on 2023/06/12 19:56
upstream KCSAN: data-race in filemap_fault / generic_write_end (4) ext4 3 1004d 1087d 0/26 auto-closed as invalid on 2021/07/08 19:40
upstream KCSAN: data-race in filemap_fault / generic_write_end (6) ext4 43 649d 754d 0/26 auto-closed as invalid on 2022/06/28 10:53
upstream KCSAN: data-race in filemap_fault / generic_write_end (7) ext4 1 519d 519d 0/26 auto-obsoleted due to no activity on 2022/11/05 12:50
upstream KCSAN: data-race in filemap_fault / generic_write_end (2) ext4 1 1320d 1320d 0/26 auto-closed as invalid on 2020/08/26 18:57
upstream KCSAN: data-race in filemap_fault / generic_write_end ext4 1 1491d 1430d 0/26 auto-closed as invalid on 2020/04/17 11:16
upstream KCSAN: data-race in filemap_fault / generic_write_end (5) ext4 3 927d 962d 0/26 auto-closed as invalid on 2021/09/23 14:23

Sample crash report:
loop2: detected capacity change from 0 to 128
==================================================================
BUG: KCSAN: data-race in filemap_fault / generic_write_end

write to 0xffff88813a89ca00 of 8 bytes by task 19739 on cpu 1:
 i_size_write include/linux/fs.h:932 [inline]
 generic_write_end+0x94/0x230 fs/buffer.c:2291
 fat_write_end+0x4e/0x160 fs/fat/inode.c:244
 cont_expand_zero fs/buffer.c:2514 [inline]
 cont_write_begin+0x2c0/0x690 fs/buffer.c:2572
 fat_write_begin+0x61/0xf0 fs/fat/inode.c:230
 generic_cont_expand_simple+0xa7/0x140 fs/buffer.c:2473
 fat_cont_expand+0x3a/0x160 fs/fat/file.c:223
 fat_fallocate+0x182/0x1d0 fs/fat/file.c:301
 vfs_fallocate+0x378/0x3e0 fs/open.c:324
 ksys_fallocate fs/open.c:347 [inline]
 __do_sys_fallocate fs/open.c:355 [inline]
 __se_sys_fallocate fs/open.c:353 [inline]
 __x64_sys_fallocate+0x79/0xc0 fs/open.c:353
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88813a89ca00 of 8 bytes by task 19735 on cpu 0:
 i_size_read include/linux/fs.h:910 [inline]
 filemap_fault+0x91/0xc30 mm/filemap.c:3209
 __do_fault mm/memory.c:4265 [inline]
 do_read_fault mm/memory.c:4628 [inline]
 do_fault mm/memory.c:4762 [inline]
 do_pte_missing mm/memory.c:3730 [inline]
 handle_pte_fault mm/memory.c:5038 [inline]
 __handle_mm_fault mm/memory.c:5179 [inline]
 handle_mm_fault+0x13bd/0x2dd0 mm/memory.c:5344
 faultin_page mm/gup.c:956 [inline]
 __get_user_pages+0x402/0xe40 mm/gup.c:1239
 populate_vma_page_range mm/gup.c:1677 [inline]
 __mm_populate+0x216/0x330 mm/gup.c:1786
 mm_populate include/linux/mm.h:3379 [inline]
 vm_mmap_pgoff+0x1a7/0x240 mm/util.c:551
 ksys_mmap_pgoff+0x2b8/0x330 mm/mmap.c:1425
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000012000 -> 0x0000000000014000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 19735 Comm: syz-executor.2 Not tainted 6.6.0-syzkaller-12715-g6bdfe2d88b9f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/04 07:09 upstream 6bdfe2d88b9f 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_fault / generic_write_end
2023/10/23 05:53 upstream 05d3ef8bba77 361b23dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_fault / generic_write_end
* Struck through repros no longer work on HEAD.