syzbot


KCSAN: data-race in filemap_splice_read / simple_write_end

Status: auto-obsoleted due to no activity on 2023/08/15 05:33
Subsystems: fs
[Documentation on labels]
First crash: 571d, last: 567d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in filemap_splice_read / simple_write_end (2) fs 1 486d 485d 0/28 auto-obsoleted due to no activity on 2023/11/04 22:01
upstream KCSAN: data-race in filemap_splice_read / simple_write_end (3) fs 2 436d 414d 0/28 auto-obsoleted due to no activity on 2023/12/25 00:04

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

write to 0xffff88810a8c98b0 of 8 bytes by task 16194 on cpu 1:
 i_size_write include/linux/fs.h:901 [inline]
 simple_write_end+0x22d/0x410 fs/libfs.c:614
 generic_perform_write+0x26d/0x410 mm/filemap.c:3934
 __generic_file_write_iter+0xa1/0x120 mm/filemap.c:4018
 generic_file_write_iter+0x7d/0x1c0 mm/filemap.c:4044
 do_iter_write+0x4b4/0x7b0 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:739
 do_splice_from fs/splice.c:934 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1143
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1089
 do_splice_direct+0x10d/0x190 fs/splice.c:1195
 do_sendfile+0x3b6/0x9a0 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810a8c98b0 of 8 bytes by task 16192 on cpu 0:
 i_size_read include/linux/fs.h:879 [inline]
 filemap_splice_read+0x1a0/0x810 mm/filemap.c:2921
 vfs_splice_read fs/splice.c:994 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1070
 do_splice_direct+0x10d/0x190 fs/splice.c:1195
 do_sendfile+0x3b6/0x9a0 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000001c47000 -> 0x0000000001c50200

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16192 Comm: syz-executor.2 Not tainted 6.5.0-rc1-syzkaller-00006-g3f01e9fed845 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
==================================================================
==================================================================
BUG: KCSAN: data-race in filemap_splice_read / filemap_splice_read

write to 0xffff888112f47290 of 8 bytes by task 16194 on cpu 1:
 filemap_splice_read+0x5be/0x810 mm/filemap.c:2971
 vfs_splice_read fs/splice.c:994 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1070
 do_splice_direct+0x10d/0x190 fs/splice.c:1195
 do_sendfile+0x3b6/0x9a0 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

write to 0xffff888112f47290 of 8 bytes by task 16192 on cpu 0:
 filemap_splice_read+0x5be/0x810 mm/filemap.c:2971
 vfs_splice_read fs/splice.c:994 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1070
 do_splice_direct+0x10d/0x190 fs/splice.c:1195
 do_sendfile+0x3b6/0x9a0 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000002d19000 -> 0x00000000068af000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16192 Comm: syz-executor.2 Not tainted 6.5.0-rc1-syzkaller-00006-g3f01e9fed845 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/11 05:31 upstream 3f01e9fed845 52ae002a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_splice_read / simple_write_end
2023/07/07 19:07 upstream 5133c9e51de4 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_splice_read / simple_write_end
* Struck through repros no longer work on HEAD.