> Hello, > > syzbot found the following issue on: > > HEAD commit: c674aa7c289e Add linux-next specific files for 20250212 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=125063f8580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a0fd539126ae5541 > dashboard link: https://syzkaller.appspot.com/bug?extid=c104904eeb2c0edbdb06 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=158a3bdf980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17e18aa4580000 #syz test diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 68c943a77e41..354d77f9228b 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1972,7 +1972,8 @@ static void loop_process_work(struct loop_worker *worker, * *and* the worker will not run again which ensures that it * is safe to free any worker on the idle list */ - if (worker && !work_pending(&worker->work)) { + if (worker && !work_pending(&worker->work) + && list_empty(&worker->idle_list)) { worker->last_ran_at = jiffies; list_add_tail(&worker->idle_list, &lo->idle_worker_list); loop_set_timer(lo); > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/cc5b357d26d3/disk-c674aa7c.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/11dcf272a27b/vmlinux-c674aa7c.xz > kernel image: https://storage.googleapis.com/syzbot-assets/4e487b1c1c6e/bzImage-c674aa7c.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/4ea41e9eae4d/mount_0.gz > > The issue was bisected to: > > commit 3bee991f2b68175c828dc3f9c26367fe1827319a > Author: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx> > Date: Fri Feb 7 09:19:42 2025 +0000 > > loop: release the lo_work_lock before queue_work > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=161029b0580000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=151029b0580000 > console output: https://syzkaller.appspot.com/x/log.txt?x=111029b0580000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+c104904eeb2c0edbdb06@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 3bee991f2b68 ("loop: release the lo_work_lock before queue_work") > > list_add double add: new=ffff88807fe21c70, prev=ffff88807fe21c70, next=ffff888024c29160. > ------------[ cut here ]------------ > kernel BUG at lib/list_debug.c:37! > Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI > CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:1 Not tainted 6.14.0-rc2-next-20250212-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 > Workqueue: loop0 loop_workfn > RIP: 0010:__list_add_valid_or_report+0xa4/0x130 lib/list_debug.c:35 > Code: f7 74 11 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 48 c7 c7 40 e5 60 8c 4c 89 fe 4c 89 e2 4c 89 f1 e8 fd 88 35 fc 90 <0f> 0b 48 c7 c7 40 e3 60 8c e8 ee 88 35 fc 90 0f 0b 48 c7 c7 e0 e3 > RSP: 0018:ffffc90000117628 EFLAGS: 00010046 > RAX: 0000000000000058 RBX: 1ffff1100ffc438e RCX: 89e05f8d6ffcb000 > RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 > RBP: 1ffff1100498522d R08: ffffffff819f562c R09: 1ffff92000022e60 > R10: dffffc0000000000 R11: fffff52000022e61 R12: ffff88807fe21c70 > R13: dffffc0000000000 R14: ffff888024c29160 R15: ffff88807fe21c70 > FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ff4b64ffe00 CR3: 000000007cfa4000 CR4: 00000000003526f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > __list_add_valid include/linux/list.h:88 [inline] > __list_add include/linux/list.h:150 [inline] > list_add_tail include/linux/list.h:183 [inline] > loop_process_work+0x1f96/0x21c0 drivers/block/loop.c:1977 > process_one_work kernel/workqueue.c:3236 [inline] > process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 > worker_thread+0x870/0xd30 kernel/workqueue.c:3398 > kthread+0x7a9/0x920 kernel/kthread.c:464 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > </TASK> > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:__list_add_valid_or_report+0xa4/0x130 lib/list_debug.c:35 > Code: f7 74 11 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 48 c7 c7 40 e5 60 8c 4c 89 fe 4c 89 e2 4c 89 f1 e8 fd 88 35 fc 90 <0f> 0b 48 c7 c7 40 e3 60 8c e8 ee 88 35 fc 90 0f 0b 48 c7 c7 e0 e3 > RSP: 0018:ffffc90000117628 EFLAGS: 00010046 > RAX: 0000000000000058 RBX: 1ffff1100ffc438e RCX: 89e05f8d6ffcb000 > RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 > RBP: 1ffff1100498522d R08: ffffffff819f562c R09: 1ffff92000022e60 > R10: dffffc0000000000 R11: fffff52000022e61 R12: ffff88807fe21c70 > R13: dffffc0000000000 R14: ffff888024c29160 R15: ffff88807fe21c70 > FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ff4b64ffe00 CR3: 000000007cfa4000 CR4: 00000000003526f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want syzbot to run the reproducer, reply with: > #syz test: git://repo/address.git branch-or-commit-hash > If you attach or paste a git patch, syzbot will apply it before testing. > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup
