syzbot


KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read

Status: moderation: reported on 2023/12/09 00:01
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+706dde8a3e5ef992fcad@syzkaller.appspotmail.com
First crash: 799d, last: 6h43m

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

write to 0xffff888113486168 of 8 bytes by task 31700 on cpu 0:
 shmem_file_splice_read+0x470/0x600 mm/shmem.c:3677
 do_splice_read fs/splice.c:982 [inline]
 splice_direct_to_actor+0x26f/0x680 fs/splice.c:1086
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1230
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0x2bb0/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:41
 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

write to 0xffff888113486168 of 8 bytes by task 31702 on cpu 1:
 shmem_file_splice_read+0x470/0x600 mm/shmem.c:3677
 do_splice_read fs/splice.c:982 [inline]
 splice_direct_to_actor+0x26f/0x680 fs/splice.c:1086
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1230
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0x2bb0/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:41
 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: 0x000000000002c55f -> 0x000000000002c5e3

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 31702 Comm: syz.5.11477 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================

Crashes (1860):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/17 19:54 upstream d4b779985a6c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/16 23:40 upstream 5aca7966d2a7 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/16 00:15 upstream 46a51f4f5eda e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/15 10:53 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/14 21:51 upstream 79e8447ec662 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/14 08:25 upstream f83a4f2a4d8c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/13 19:14 upstream 5cd64d4f9268 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/12 09:28 upstream 320475fbd590 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/11 20:00 upstream 02ffd6f89c50 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/11 16:09 upstream 02ffd6f89c50 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/10 20:56 upstream 7aac71907bde fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/10 00:35 upstream 9dd1835ecda5 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/09 20:08 upstream 9dd1835ecda5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/08 19:31 upstream f777d1112ee5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/08 06:08 upstream 76eeb9b8de98 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/07 16:44 upstream 6ab41fca2e80 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/06 22:46 upstream b236920731dd d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/06 09:09 upstream d1d10cea0895 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/05 20:01 upstream c8ed9b5c02a5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/05 06:31 upstream d69eb204c255 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/04 17:11 upstream 08b06c30a445 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/04 04:04 upstream b9a10f876409 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/03 20:20 upstream ec299e4dc21e 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/02 21:59 upstream e6b9dce0aeeb 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/02 13:37 upstream b320789d6883 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/09/01 07:27 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/31 18:04 upstream 5c3b3264e585 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/31 01:44 upstream c8bc81a52d5a 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/30 12:21 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/29 22:56 upstream fb679c832b64 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/29 17:48 upstream fb679c832b64 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/29 09:54 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/28 20:27 upstream 07d9df80082b d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/28 07:56 upstream 07d9df80082b e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/27 18:38 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/26 16:18 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/26 16:15 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/26 05:47 upstream fab1beda7597 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/25 16:16 upstream b6add54ba618 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/24 15:35 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/23 20:30 upstream 8d245acc1e88 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/23 07:03 upstream 6debb6904172 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/22 17:47 upstream cf6fc5eefc5b bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/22 04:07 upstream 3957a5720157 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2025/08/21 14:05 upstream 068a56e56fa8 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2023/12/08 12:55 upstream 5e3f5b81de80 28b24332 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
2023/11/23 22:26 upstream d3fa86b1a7b4 5b429f39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read
* Struck through repros no longer work on HEAD.