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

Status: auto-obsoleted due to no activity on 2026/01/20 13:41
Subsystems: scsi
[Documentation on labels]
Reported-by: syzbot+61273e29fc4ceb197b73@syzkaller.appspotmail.com
First crash: 259d, last: 259d
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
fc987338 assessment-kcsan Benign: ✅ ❓ KCSAN: data-race in sg_open / sg_open (2) 2026/01/09 17:05 2026/01/09 17:05 2026/01/09 17:27 75199160
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in sg_open / sg_open scsi 6 1 382d 382d 0/29 auto-obsoleted due to no activity on 2025/09/19 19:42

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

read-write to 0xffff8881026ae2a8 of 4 bytes by task 22050 on cpu 0:
 sg_open+0xb8e/0xc70 drivers/scsi/sg.c:355
 chrdev_open+0x2eb/0x3a0 fs/char_dev.c:414
 do_dentry_open+0x649/0xa20 fs/open.c:965
 vfs_open+0x37/0x1e0 fs/open.c:1097
 do_open fs/namei.c:3975 [inline]
 path_openat+0x1c5e/0x2170 fs/namei.c:4134
 do_filp_open+0x109/0x230 fs/namei.c:4161
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x2eab/0x3000 arch/x86/include/generated/asm/syscalls_64.h:258
 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

read to 0xffff8881026ae2a8 of 4 bytes by task 22026 on cpu 1:
 open_wait drivers/scsi/sg.c:253 [inline]
 sg_open+0x608/0xc70 drivers/scsi/sg.c:334
 chrdev_open+0x2eb/0x3a0 fs/char_dev.c:414
 do_dentry_open+0x649/0xa20 fs/open.c:965
 vfs_open+0x37/0x1e0 fs/open.c:1097
 do_open fs/namei.c:3975 [inline]
 path_openat+0x1c5e/0x2170 fs/namei.c:4134
 do_filp_open+0x109/0x230 fs/namei.c:4161
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x2eab/0x3000 arch/x86/include/generated/asm/syscalls_64.h:258
 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: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 22026 Comm: syz.6.6227 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/25 13:40 upstream ac3fd01e4c1e 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in sg_open / sg_open
* Struck through repros no longer work on HEAD.