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KCSAN: data-race in filemap_read / filemap_read (2)

Status: auto-obsoleted due to no activity on 2024/01/26 23:06
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+40ccd616d7c46b368c0f@syzkaller.appspotmail.com
First crash: 620d, last: 618d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in filemap_read / filemap_read (6) fs 6 146 11h04m 77d 0/29 moderation: reported on 2025/06/15 13:14
upstream KCSAN: data-race in filemap_read / filemap_read (5) fs 6 1 158d 158d 0/29 auto-obsoleted due to no activity on 2025/05/22 02:24
upstream KCSAN: data-race in filemap_read / filemap_read fs 6 832 648d 1487d 0/29 auto-obsoleted due to no activity on 2023/12/20 06:43
upstream KCSAN: data-race in filemap_read / filemap_read (3) fs 6 4 525d 559d 0/29 auto-obsoleted due to no activity on 2024/04/29 01:22
upstream KCSAN: data-race in filemap_read / filemap_read (4) fs 6 1 425d 425d 0/29 auto-obsoleted due to no activity on 2024/08/06 15:23

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

read to 0xffff88813c674b90 of 8 bytes by task 8032 on cpu 1:
 filemap_read+0x89/0x680 mm/filemap.c:2569
 generic_file_read_iter+0x78/0x330 mm/filemap.c:2772
 ext4_file_read_iter+0x1d8/0x2a0
 call_read_iter include/linux/fs.h:2014 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:364
 vfs_splice_read fs/splice.c:992 [inline]
 splice_direct_to_actor+0x2aa/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 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

write to 0xffff88813c674b90 of 8 bytes by task 8040 on cpu 0:
 filemap_read+0x605/0x680 mm/filemap.c:2662
 generic_file_read_iter+0x78/0x330 mm/filemap.c:2772
 ext4_file_read_iter+0x1d8/0x2a0
 call_read_iter include/linux/fs.h:2014 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:364
 vfs_splice_read fs/splice.c:992 [inline]
 splice_direct_to_actor+0x2aa/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 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: 0x0000000000000e4b -> 0x0000000000000e4c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8040 Comm: syz-executor.2 Not tainted 6.7.0-rc6-syzkaller-00176-g24e0d2e527a3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/22 23:05 upstream 24e0d2e527a3 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_read / filemap_read
2023/12/20 07:49 upstream 55cb5f43689d 3ad490ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_read / filemap_read
* Struck through repros no longer work on HEAD.