syzbot


KCSAN: data-race in sg_fill_request_table / sg_rq_end_io (3)

Status: moderation: reported on 2026/04/27 09:56
Subsystems: scsi
[Documentation on labels]
Reported-by: syzbot+82c7fc080122cd8d1f25@syzkaller.appspotmail.com
First crash: 14h29m, last: 14h29m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
a0995302-fbba-49d1-8ff6-f088407c8967 assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in sg_fill_request_table / sg_rq_end_io (3) 2026/04/27 09:56 2026/04/27 09:56 2026/04/27 10:16 9c2d0995bb06e7518555bd3b755e327c89b59823
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in sg_fill_request_table / sg_rq_end_io (2) scsi 6 2 144d 181d 0/29 auto-obsoleted due to no activity on 2026/01/29 22:38
upstream KCSAN: data-race in sg_fill_request_table / sg_rq_end_io scsi 6 2 324d 335d 0/29 auto-obsoleted due to no activity on 2025/08/02 18:09

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

write to 0xffff88812022c109 of 1 bytes by interrupt on cpu 1:
 sg_rq_end_io+0x158/0x770 drivers/scsi/sg.c:1348
 __blk_mq_end_request+0x2f4/0x370 block/blk-mq.c:1168
 scsi_end_request+0x29c/0x4c0 drivers/scsi/scsi_lib.c:681
 scsi_io_completion+0x194/0x1d0 drivers/scsi/scsi_lib.c:1095
 scsi_finish_command+0x1c7/0x1e0 drivers/scsi/scsi.c:198
 scsi_complete+0x155/0x4f0 drivers/scsi/scsi_lib.c:1569
 blk_complete_reqs block/blk-mq.c:1253 [inline]
 blk_done_softirq+0x77/0xb0 block/blk-mq.c:1258
 handle_softirqs+0xb9/0x280 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x42/0xd0 kernel/softirq.c:735
 common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:326
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
 syscall_enter_from_user_mode_work include/linux/entry-common.h:144 [inline]
 syscall_enter_from_user_mode include/linux/entry-common.h:178 [inline]
 do_syscall_64+0x82/0x3b0 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88812022c109 of 1 bytes by task 24144 on cpu 0:
 sg_fill_request_table+0x5f/0x1d0 drivers/scsi/sg.c:867
 sg_ioctl_common drivers/scsi/sg.c:1084 [inline]
 sg_ioctl+0x6a6/0x1340 drivers/scsi/sg.c:1158
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1563/0x3020 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 24144 Comm: syz.3.9360 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/27 09:56 upstream 254f49634ee1 0f700595 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in sg_fill_request_table / sg_rq_end_io
* Struck through repros no longer work on HEAD.