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KCSAN: data-race in filemap_read / filemap_read (5)

Status: auto-obsoleted due to no activity on 2025/05/22 02:24
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+d19a771491d23a5abd3a@syzkaller.appspotmail.com
First crash: 225d, last: 225d
▶ ▼ 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 6 280 13h48m 145d 0/29 moderation: reported on 2025/06/15 13:14
upstream KCSAN: data-race in filemap_read / filemap_read fs 6 832 716d 1555d 0/29 auto-obsoleted due to no activity on 2023/12/20 06:43
upstream KCSAN: data-race in filemap_read / filemap_read (2) fs 6 2 686d 688d 0/29 auto-obsoleted due to no activity on 2024/01/26 23:06
upstream KCSAN: data-race in filemap_read / filemap_read (3) fs 6 4 592d 627d 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 493d 493d 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 0xffff8881034b75e8 of 8 bytes by task 16625 on cpu 1:
 filemap_read+0x85/0x8d0 mm/filemap.c:2675
 generic_file_read_iter+0x78/0x330 mm/filemap.c:2893
 ext4_file_read_iter+0x1cc/0x290 fs/ext4/file.c:-1
 copy_splice_read+0x390/0x5d0 fs/splice.c:363
 do_splice_read fs/splice.c:978 [inline]
 splice_direct_to_actor+0x28e/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff8881034b75e8 of 8 bytes by task 16630 on cpu 0:
 filemap_read+0x842/0x8d0 mm/filemap.c:2774
 generic_file_read_iter+0x78/0x330 mm/filemap.c:2893
 ext4_file_read_iter+0x1cc/0x290 fs/ext4/file.c:-1
 copy_splice_read+0x390/0x5d0 fs/splice.c:363
 do_splice_read fs/splice.c:978 [inline]
 splice_direct_to_actor+0x28e/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000323 -> 0x0000000000000324

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 16630 Comm: syz.5.4778 Not tainted 6.14.0-syzkaller-03576-g1e1ba8d23dae #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/27 02:24 upstream 1e1ba8d23dae 20510e88 .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.