[syzbot] [kernel?] kernel BUG in qlist_free_all (2)

[syzbot] [kernel?] kernel BUG in qlist_free_all (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    9dd1835ecda5 Merge tag 'dma-mapping-6.17-2025-09-09' of gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1663cb12580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e0bea6c0b97a2002
dashboard link: https://syzkaller.appspot.com/bug?extid=8715dd783e9b0bef43b1
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3bd34622db2f/disk-9dd1835e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/673ef735e573/vmlinux-9dd1835e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/eb16aa1b210d/bzImage-9dd1835e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8715dd783e9b0bef43b1@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at arch/x86/mm/physaddr.c:28!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 456 Comm: syz-executor Tainted: G     U              syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__phys_addr+0xfa/0x180 arch/x86/mm/physaddr.c:28
Code: 48 d3 e8 48 89 c3 48 89 c6 e8 82 80 4e 00 48 85 db 75 11 e8 08 85 4e 00 48 89 e8 5b 5d 41 5c c3 cc cc cc cc e8 f7 84 4e 00 90 <0f> 0b e8 ef 84 4e 00 48 c7 c0 10 b0 3a 8e 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc9000c6f74b0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 3fffff890062e864 RCX: ffffffff816c85f3
RDX: ffff8880255bda00 RSI: ffffffff816c8679 RDI: 0000000000000006
RBP: 400077088062e864 R08: 0000000000000006 R09: 3fffff890062e864
R10: 400077088062e864 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc9000c6f7508 R15: ffff888022aa0001
FS:  0000555589044500(0000) GS:ffff8881247bd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1fea5056c0 CR3: 0000000076f3e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 virt_to_folio include/linux/mm.h:1180 [inline]
 virt_to_slab mm/slab.h:187 [inline]
 qlink_to_cache mm/kasan/quarantine.c:131 [inline]
 qlist_free_all+0x65/0x120 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4247
 ptlock_alloc+0x1f/0x70 mm/memory.c:7161
 ptlock_init include/linux/mm.h:2953 [inline]
 pagetable_pte_ctor include/linux/mm.h:3002 [inline]
 __pte_alloc_one_noprof include/asm-generic/pgalloc.h:78 [inline]
 pte_alloc_one+0x82/0x3a0 arch/x86/mm/pgtable.c:18
 __pte_alloc+0x6d/0x3c0 mm/memory.c:452
 copy_pte_range mm/memory.c:1107 [inline]
 copy_pmd_range mm/memory.c:1261 [inline]
 copy_pud_range mm/memory.c:1298 [inline]
 copy_p4d_range mm/memory.c:1322 [inline]
 copy_page_range+0x3b83/0x5c80 mm/memory.c:1410
 dup_mmap+0xe88/0x21d0 mm/mmap.c:1834
 dup_mm kernel/fork.c:1485 [inline]
 copy_mm kernel/fork.c:1537 [inline]
 copy_process+0x4081/0x7690 kernel/fork.c:2175
 kernel_clone+0xfc/0x930 kernel/fork.c:2605
 __do_sys_clone+0xce/0x120 kernel/fork.c:2748
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1fe9785413
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffd86810ba8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1fe9785413
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555890447d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 0000000000164bcc R15: 00007ffd86810d40
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__phys_addr+0xfa/0x180 arch/x86/mm/physaddr.c:28
Code: 48 d3 e8 48 89 c3 48 89 c6 e8 82 80 4e 00 48 85 db 75 11 e8 08 85 4e 00 48 89 e8 5b 5d 41 5c c3 cc cc cc cc e8 f7 84 4e 00 90 <0f> 0b e8 ef 84 4e 00 48 c7 c0 10 b0 3a 8e 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc9000c6f74b0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 3fffff890062e864 RCX: ffffffff816c85f3
RDX: ffff8880255bda00 RSI: ffffffff816c8679 RDI: 0000000000000006
RBP: 400077088062e864 R08: 0000000000000006 R09: 3fffff890062e864
R10: 400077088062e864 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc9000c6f7508 R15: ffff888022aa0001
FS:  0000555589044500(0000) GS:ffff8881247bd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000800000 CR3: 0000000076f3e000 CR4: 00000000003526f0


---
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Re: [syzbot] [fs?] kernel BUG in qlist_free_all (2)

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    7f7072574127 Merge tag 'kbuild-6.18-1' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1234b092580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b78ebc06b51acd7e
dashboard link: https://syzkaller.appspot.com/bug?extid=8715dd783e9b0bef43b1
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11bc1092580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=176bfd04580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/70468cf24114/disk-7f707257.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8126ac85fc8f/vmlinux-7f707257.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0b72e383dd9d/bzImage-7f707257.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8715dd783e9b0bef43b1@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at arch/x86/mm/physaddr.c:28!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5927 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__phys_addr+0x173/0x180 arch/x86/mm/physaddr.c:28
Code: e8 72 22 49 00 48 c7 c7 90 ce 21 8d 48 89 de 4c 89 f2 e8 b0 03 39 03 e9 4d ff ff ff e8 56 22 49 00 90 0f 0b e8 4e 22 49 00 90 <0f> 0b e8 46 22 49 00 90 0f 0b 0f 1f 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003fbfcd8 EFLAGS: 00010293
RAX: ffffffff81740d22 RBX: 0000607fffd49468 RCX: ffff8880256c1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffe8ffffd49468 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d6b7e7 R12: ffffea0000000000
R13: 0000000000000000 R14: 000000000000002e R15: 0000000000000001
FS:  000055558ba17500(0000) GS:ffff888127122000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc7f61af40 CR3: 00000000350ca000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 virt_to_folio include/linux/mm.h:1180 [inline]
 virt_to_slab mm/slab.h:187 [inline]
 qlink_to_cache mm/kasan/quarantine.c:131 [inline]
 qlist_free_all+0x39/0x140 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 kmem_cache_alloc_noprof+0x114/0x2d0 mm/slub.c:4247
 getname_flags+0xb8/0x540 fs/namei.c:146
 user_path_at+0x24/0x60 fs/namei.c:3214
 ksys_umount fs/namespace.c:2055 [inline]
 __do_sys_umount fs/namespace.c:2063 [inline]
 __se_sys_umount fs/namespace.c:2061 [inline]
 __x64_sys_umount+0xee/0x160 fs/namespace.c:2061
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f62cb4c01f7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc7f61a098 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f62cb541d7d RCX: 00007f62cb4c01f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc7f61b1e0
RBP: 00007ffc7f61b1cc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc7f61b1e0
R13: 00007f62cb541d7d R14: 0000000000022677 R15: 00007ffc7f61b220
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__phys_addr+0x173/0x180 arch/x86/mm/physaddr.c:28
Code: e8 72 22 49 00 48 c7 c7 90 ce 21 8d 48 89 de 4c 89 f2 e8 b0 03 39 03 e9 4d ff ff ff e8 56 22 49 00 90 0f 0b e8 4e 22 49 00 90 <0f> 0b e8 46 22 49 00 90 0f 0b 0f 1f 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003fbfcd8 EFLAGS: 00010293
RAX: ffffffff81740d22 RBX: 0000607fffd49468 RCX: ffff8880256c1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffe8ffffd49468 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d6b7e7 R12: ffffea0000000000
R13: 0000000000000000 R14: 000000000000002e R15: 0000000000000001
FS:  000055558ba17500(0000) GS:ffff888127122000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc7f61af40 CR3: 00000000350ca000 CR4: 00000000003526f0


---
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If you attach or paste a git patch, syzbot will apply it before testing.

Re: [syzbot] [fs?] kernel BUG in qlist_free_all (2)

[syzbot]

syzbot has bisected this issue to:

commit 3253cb49cbad4772389d6ef55be75db1f97da910
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Thu Sep 4 14:25:25 2025 +0000

    softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17566a7c580000
start commit:   7f7072574127 Merge tag 'kbuild-6.18-1' of git://git.kernel..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=14d66a7c580000
console output: https://syzkaller.appspot.com/x/log.txt?x=10d66a7c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b78ebc06b51acd7e
dashboard link: https://syzkaller.appspot.com/bug?extid=8715dd783e9b0bef43b1
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16ba76e2580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17741ee2580000

Reported-by: syzbot+8715dd783e9b0bef43b1@syzkaller.appspotmail.com
Fixes: 3253cb49cbad ("softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection