* [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock
@ 2024-12-05 17:48 syzbot
2024-12-11 19:52 ` Tejun Heo
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: syzbot @ 2024-12-05 17:48 UTC (permalink / raw)
To: cgroups, hannes, linux-kernel, mkoutny, netdev, syzkaller-bugs,
tj
Hello,
syzbot found the following issue on:
HEAD commit: 932fc2f19b74 Merge branch 'irq-save-restore'
git tree: bpf-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=14fd6330580000
kernel config: https://syzkaller.appspot.com/x/.config?x=50c7a61469ce77e7
dashboard link: https://syzkaller.appspot.com/bug?extid=31eb4d4e7d9bc1fc1312
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=161cdfc0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12dfc8df980000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/afd76657938b/disk-932fc2f1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5ab299e9b5df/vmlinux-932fc2f1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6617519fa7b9/bzImage-932fc2f1.xz
Bisection is inconclusive: the first bad commit could be any of:
42d9e8b7ccdd Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
9f16d5e6f220 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=121e8020580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+31eb4d4e7d9bc1fc1312@syzkaller.appspotmail.com
RBP: 0000000000000001 R08: 00007ffee33edd87 R09: 00007fe28ebf71e7
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffee33ee00c
R13: 00007ffee33ee030 R14: 00007ffee33ee070 R15: 0000000000000001
</TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 UID: 0 PID: 5842 Comm: syz-executor126 Not tainted 6.13.0-rc1-syzkaller-00032-g932fc2f19b74 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:do_perf_trace_cgroup_rstat include/trace/events/cgroup.h:207 [inline]
RIP: 0010:perf_trace_cgroup_rstat+0x2b2/0x580 include/trace/events/cgroup.h:207
Code: 8d 98 58 04 00 00 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 fc 0c 75 00 48 8b 1b 48 83 c3 0c 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 d5 01 00 00 44 8b 2b 49 8d 5f 08 48 89
RSP: 0018:ffffc90003837a80 EFLAGS: 00010003
RAX: 0000000000000001 RBX: 000000000000000c RCX: ffff8880345ada00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880b8737768
RBP: ffffc90003837b70 R08: ffffffff81a90e9b R09: 1ffffffff20328d6
R10: dffffc0000000000 R11: fffffbfff20328d7 R12: ffff8880b87376e0
R13: 1ffff92000706f5c R14: dffffc0000000000 R15: ffffe8ffffd30be8
FS: 000055558b3013c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000050c CR3: 00000000329de000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
trace_cgroup_rstat_locked include/trace/events/cgroup.h:242 [inline]
__cgroup_rstat_lock+0x3e1/0x590 kernel/cgroup/rstat.c:292
cgroup_rstat_flush+0x30/0x50 kernel/cgroup/rstat.c:353
cgroup_rstat_exit+0x27/0x1e0 kernel/cgroup/rstat.c:411
cgroup_create kernel/cgroup/cgroup.c:5782 [inline]
cgroup_mkdir+0x53a/0xd60 kernel/cgroup/cgroup.c:5831
kernfs_iop_mkdir+0x253/0x3f0 fs/kernfs/dir.c:1246
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4311
do_mkdirat+0x264/0x3a0 fs/namei.c:4334
__do_sys_mkdir fs/namei.c:4354 [inline]
__se_sys_mkdir fs/namei.c:4352 [inline]
__x64_sys_mkdir+0x6c/0x80 fs/namei.c:4352
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe28eba7a19
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 1d 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffee33edfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fe28eba7a19
RDX: 0000000000000000 RSI: d0939199c36b4d28 RDI: 0000000020000000
RBP: 0000000000000001 R08: 00007ffee33edd87 R09: 00007fe28ebf71e7
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffee33ee00c
R13: 00007ffee33ee030 R14: 00007ffee33ee070 R15: 0000000000000001
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_perf_trace_cgroup_rstat include/trace/events/cgroup.h:207 [inline]
RIP: 0010:perf_trace_cgroup_rstat+0x2b2/0x580 include/trace/events/cgroup.h:207
Code: 8d 98 58 04 00 00 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 fc 0c 75 00 48 8b 1b 48 83 c3 0c 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 d5 01 00 00 44 8b 2b 49 8d 5f 08 48 89
RSP: 0018:ffffc90003837a80 EFLAGS: 00010003
RAX: 0000000000000001 RBX: 000000000000000c RCX: ffff8880345ada00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880b8737768
RBP: ffffc90003837b70 R08: ffffffff81a90e9b R09: 1ffffffff20328d6
R10: dffffc0000000000 R11: fffffbfff20328d7 R12: ffff8880b87376e0
R13: 1ffff92000706f5c R14: dffffc0000000000 R15: ffffe8ffffd30be8
FS: 000055558b3013c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000050c CR3: 00000000329de000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 8d 98 58 04 00 00 lea 0x458(%rax),%ebx
6: 48 89 d8 mov %rbx,%rax
9: 48 c1 e8 03 shr $0x3,%rax
d: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1)
12: 74 08 je 0x1c
14: 48 89 df mov %rbx,%rdi
17: e8 fc 0c 75 00 call 0x750d18
1c: 48 8b 1b mov (%rbx),%rbx
1f: 48 83 c3 0c add $0xc,%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 d5 01 00 00 jne 0x20c
37: 44 8b 2b mov (%rbx),%r13d
3a: 49 8d 5f 08 lea 0x8(%r15),%rbx
3e: 48 rex.W
3f: 89 .byte 0x89
---
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@googlegroups.com.
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
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock
2024-12-05 17:48 [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock syzbot
@ 2024-12-11 19:52 ` Tejun Heo
2024-12-11 20:21 ` syzbot
2024-12-11 20:48 ` Tejun Heo
2025-06-01 16:21 ` syzbot
2 siblings, 1 reply; 7+ messages in thread
From: Tejun Heo @ 2024-12-11 19:52 UTC (permalink / raw)
To: syzbot; +Cc: cgroups, hannes, linux-kernel, mkoutny, netdev, syzkaller-bugs
#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git for-6.13-fixes-test
--
tejun
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock
2024-12-11 19:52 ` Tejun Heo
@ 2024-12-11 20:21 ` syzbot
0 siblings, 0 replies; 7+ messages in thread
From: syzbot @ 2024-12-11 20:21 UTC (permalink / raw)
To: cgroups, hannes, linux-kernel, mkoutny, netdev, syzkaller-bugs,
tj
Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in __cgroup_rstat_lock
RBP: 00007f388c6bb0a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007f388bb45fa0 R15: 00007fff5c4c6d18
</TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
CPU: 0 UID: 0 PID: 6756 Comm: syz.0.16 Not tainted 6.13.0-rc2-syzkaller-ge0dac4f3fa34 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:cgroup_id include/linux/cgroup.h:326 [inline]
RIP: 0010:do_perf_trace_cgroup_rstat include/trace/events/cgroup.h:207 [inline]
RIP: 0010:perf_trace_cgroup_rstat+0x30f/0x580 include/trace/events/cgroup.h:207
Code: 50 01 00 00 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 a1 75 70 00 41 bd 88 00 00 00 4c 03 2b 4c 89 e8 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 ef e8 82 75 70 00 4d 8b 6d 00 49 8d 5f
RSP: 0018:ffffc9000158fa80 EFLAGS: 00010006
RAX: 0000000000000011 RBX: ffff88807d6c8150 RCX: ffff888029e69e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b8637768
RBP: ffffc9000158fb70 R08: ffffffff81a8f8fb R09: 1ffffffff2032cae
R10: dffffc0000000000 R11: fffffbfff2032caf R12: ffff8880b86376e0
R13: 0000000000000088 R14: dffffc0000000000 R15: ffffe8ffffc38000
FS: 00007f388c6bb6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f05ffff CR3: 0000000033fbe000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
trace_cgroup_rstat_locked include/trace/events/cgroup.h:242 [inline]
__cgroup_rstat_lock+0x3e1/0x590 kernel/cgroup/rstat.c:292
cgroup_rstat_flush+0x30/0x50 kernel/cgroup/rstat.c:353
cgroup_rstat_exit+0x27/0x1e0 kernel/cgroup/rstat.c:411
cgroup_create kernel/cgroup/cgroup.c:5782 [inline]
cgroup_mkdir+0x4f8/0xd60 kernel/cgroup/cgroup.c:5831
kernfs_iop_mkdir+0x253/0x3f0 fs/kernfs/dir.c:1246
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4311
do_mkdirat+0x264/0x3a0 fs/namei.c:4334
__do_sys_mkdir fs/namei.c:4354 [inline]
__se_sys_mkdir fs/namei.c:4352 [inline]
__x64_sys_mkdir+0x6c/0x80 fs/namei.c:4352
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f388b97ff19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f388c6bb058 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f388bb45fa0 RCX: 00007f388b97ff19
RDX: 0000000000000000 RSI: d0939199c36b4d28 RDI: 0000000020000000
RBP: 00007f388c6bb0a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007f388bb45fa0 R15: 00007fff5c4c6d18
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:cgroup_id include/linux/cgroup.h:326 [inline]
RIP: 0010:do_perf_trace_cgroup_rstat include/trace/events/cgroup.h:207 [inline]
RIP: 0010:perf_trace_cgroup_rstat+0x30f/0x580 include/trace/events/cgroup.h:207
Code: 50 01 00 00 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 a1 75 70 00 41 bd 88 00 00 00 4c 03 2b 4c 89 e8 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 ef e8 82 75 70 00 4d 8b 6d 00 49 8d 5f
RSP: 0018:ffffc9000158fa80 EFLAGS: 00010006
RAX: 0000000000000011 RBX: ffff88807d6c8150 RCX: ffff888029e69e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b8637768
RBP: ffffc9000158fb70 R08: ffffffff81a8f8fb R09: 1ffffffff2032cae
R10: dffffc0000000000 R11: fffffbfff2032caf R12: ffff8880b86376e0
R13: 0000000000000088 R14: dffffc0000000000 R15: ffffe8ffffc38000
FS: 00007f388c6bb6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f05ffff CR3: 0000000033fbe000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 50 push %rax
1: 01 00 add %eax,(%rax)
3: 00 48 89 add %cl,-0x77(%rax)
6: d8 48 c1 fmuls -0x3f(%rax)
9: e8 03 42 80 3c call 0x3c804211
e: 30 00 xor %al,(%rax)
10: 74 08 je 0x1a
12: 48 89 df mov %rbx,%rdi
15: e8 a1 75 70 00 call 0x7075bb
1a: 41 bd 88 00 00 00 mov $0x88,%r13d
20: 4c 03 2b add (%rbx),%r13
23: 4c 89 e8 mov %r13,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 ef mov %r13,%rdi
34: e8 82 75 70 00 call 0x7075bb
39: 4d 8b 6d 00 mov 0x0(%r13),%r13
3d: 49 rex.WB
3e: 8d .byte 0x8d
3f: 5f pop %rdi
Tested on:
commit: e0dac4f3 test
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git for-6.13-fixes-test
console output: https://syzkaller.appspot.com/x/log.txt?x=1119bb30580000
kernel config: https://syzkaller.appspot.com/x/.config?x=fee25f93665c89ac
dashboard link: https://syzkaller.appspot.com/bug?extid=31eb4d4e7d9bc1fc1312
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
Note: no patches were applied.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock
2024-12-05 17:48 [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock syzbot
2024-12-11 19:52 ` Tejun Heo
@ 2024-12-11 20:48 ` Tejun Heo
2025-06-01 16:21 ` syzbot
2 siblings, 0 replies; 7+ messages in thread
From: Tejun Heo @ 2024-12-11 20:48 UTC (permalink / raw)
To: Jesper Dangaard Brouer
Cc: cgroups, hannes, linux-kernel, mkoutny, netdev, syzkaller-bugs,
syzbot
Jesper,
I think 21c38a3bd4ee ("cgroup/rstat: add cgroup_rstat_cpu_lock helpers and
tracepoints") is the offending commit for the following syzbot report. In
cgroup creation failure path, cgroup_rstat_exit() is called with @cgrp which
is not fully initialized / partially destroyed, which calls
__cgroup_rstat_lock() which then triggers a tracepoint which tries to deref
a NULL pointer. We'll probably have to flag this path and avoid triggering
the TP. Can you please take a look?
Thanks.
On Thu, Dec 05, 2024 at 09:48:25AM -0800, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 932fc2f19b74 Merge branch 'irq-save-restore'
> git tree: bpf-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=14fd6330580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=50c7a61469ce77e7
> dashboard link: https://syzkaller.appspot.com/bug?extid=31eb4d4e7d9bc1fc1312
> 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=161cdfc0580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12dfc8df980000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/afd76657938b/disk-932fc2f1.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/5ab299e9b5df/vmlinux-932fc2f1.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/6617519fa7b9/bzImage-932fc2f1.xz
>
> Bisection is inconclusive: the first bad commit could be any of:
>
> 42d9e8b7ccdd Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
> 9f16d5e6f220 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=121e8020580000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+31eb4d4e7d9bc1fc1312@syzkaller.appspotmail.com
>
> RBP: 0000000000000001 R08: 00007ffee33edd87 R09: 00007fe28ebf71e7
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffee33ee00c
> R13: 00007ffee33ee030 R14: 00007ffee33ee070 R15: 0000000000000001
> </TASK>
> Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
> KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> CPU: 1 UID: 0 PID: 5842 Comm: syz-executor126 Not tainted 6.13.0-rc1-syzkaller-00032-g932fc2f19b74 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> RIP: 0010:do_perf_trace_cgroup_rstat include/trace/events/cgroup.h:207 [inline]
> RIP: 0010:perf_trace_cgroup_rstat+0x2b2/0x580 include/trace/events/cgroup.h:207
> Code: 8d 98 58 04 00 00 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 fc 0c 75 00 48 8b 1b 48 83 c3 0c 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 d5 01 00 00 44 8b 2b 49 8d 5f 08 48 89
> RSP: 0018:ffffc90003837a80 EFLAGS: 00010003
> RAX: 0000000000000001 RBX: 000000000000000c RCX: ffff8880345ada00
> RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880b8737768
> RBP: ffffc90003837b70 R08: ffffffff81a90e9b R09: 1ffffffff20328d6
> R10: dffffc0000000000 R11: fffffbfff20328d7 R12: ffff8880b87376e0
> R13: 1ffff92000706f5c R14: dffffc0000000000 R15: ffffe8ffffd30be8
> FS: 000055558b3013c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000002000050c CR3: 00000000329de000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> trace_cgroup_rstat_locked include/trace/events/cgroup.h:242 [inline]
> __cgroup_rstat_lock+0x3e1/0x590 kernel/cgroup/rstat.c:292
> cgroup_rstat_flush+0x30/0x50 kernel/cgroup/rstat.c:353
> cgroup_rstat_exit+0x27/0x1e0 kernel/cgroup/rstat.c:411
> cgroup_create kernel/cgroup/cgroup.c:5782 [inline]
> cgroup_mkdir+0x53a/0xd60 kernel/cgroup/cgroup.c:5831
> kernfs_iop_mkdir+0x253/0x3f0 fs/kernfs/dir.c:1246
> vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4311
> do_mkdirat+0x264/0x3a0 fs/namei.c:4334
> __do_sys_mkdir fs/namei.c:4354 [inline]
> __se_sys_mkdir fs/namei.c:4352 [inline]
> __x64_sys_mkdir+0x6c/0x80 fs/namei.c:4352
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7fe28eba7a19
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 1d 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffee33edfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fe28eba7a19
> RDX: 0000000000000000 RSI: d0939199c36b4d28 RDI: 0000000020000000
> RBP: 0000000000000001 R08: 00007ffee33edd87 R09: 00007fe28ebf71e7
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffee33ee00c
> R13: 00007ffee33ee030 R14: 00007ffee33ee070 R15: 0000000000000001
> </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:do_perf_trace_cgroup_rstat include/trace/events/cgroup.h:207 [inline]
> RIP: 0010:perf_trace_cgroup_rstat+0x2b2/0x580 include/trace/events/cgroup.h:207
> Code: 8d 98 58 04 00 00 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 fc 0c 75 00 48 8b 1b 48 83 c3 0c 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 d5 01 00 00 44 8b 2b 49 8d 5f 08 48 89
> RSP: 0018:ffffc90003837a80 EFLAGS: 00010003
> RAX: 0000000000000001 RBX: 000000000000000c RCX: ffff8880345ada00
> RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880b8737768
> RBP: ffffc90003837b70 R08: ffffffff81a90e9b R09: 1ffffffff20328d6
> R10: dffffc0000000000 R11: fffffbfff20328d7 R12: ffff8880b87376e0
> R13: 1ffff92000706f5c R14: dffffc0000000000 R15: ffffe8ffffd30be8
> FS: 000055558b3013c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000002000050c CR3: 00000000329de000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
> 0: 8d 98 58 04 00 00 lea 0x458(%rax),%ebx
> 6: 48 89 d8 mov %rbx,%rax
> 9: 48 c1 e8 03 shr $0x3,%rax
> d: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1)
> 12: 74 08 je 0x1c
> 14: 48 89 df mov %rbx,%rdi
> 17: e8 fc 0c 75 00 call 0x750d18
> 1c: 48 8b 1b mov (%rbx),%rbx
> 1f: 48 83 c3 0c add $0xc,%rbx
> 23: 48 89 d8 mov %rbx,%rax
> 26: 48 c1 e8 03 shr $0x3,%rax
> * 2a: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax <-- trapping instruction
> 2f: 84 c0 test %al,%al
> 31: 0f 85 d5 01 00 00 jne 0x20c
> 37: 44 8b 2b mov (%rbx),%r13d
> 3a: 49 8d 5f 08 lea 0x8(%r15),%rbx
> 3e: 48 rex.W
> 3f: 89 .byte 0x89
>
>
> ---
> 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@googlegroups.com.
>
> 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
--
tejun
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock
2024-12-05 17:48 [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock syzbot
2024-12-11 19:52 ` Tejun Heo
2024-12-11 20:48 ` Tejun Heo
@ 2025-06-01 16:21 ` syzbot
2025-06-02 14:15 ` Michal Koutný
2 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2025-06-01 16:21 UTC (permalink / raw)
To: akpm, andrii, ast, axboe, bpf, cgroups, daniel, eddyz87, hannes,
haoluo, hawk, inwardvessel, john.fastabend, jolsa, josef, kpsingh,
linux-block, linux-kernel, linux-kselftest, linux-mm, martin.lau,
mhocko, mkoutny, muchun.song, mykolal, netdev, roman.gushchin,
sdf, shakeel.butt, shuah, song, syzkaller-bugs, tj, yonghong.song
syzbot suspects this issue was fixed by commit:
commit a97915559f5c5ff1972d678b94fd460c72a3b5f2
Author: JP Kobryn <inwardvessel@gmail.com>
Date: Fri Apr 4 01:10:48 2025 +0000
cgroup: change rstat function signatures from cgroup-based to css-based
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12ca4c82580000
start commit: 932fc2f19b74 Merge branch 'irq-save-restore'
git tree: bpf-next
kernel config: https://syzkaller.appspot.com/x/.config?x=50c7a61469ce77e7
dashboard link: https://syzkaller.appspot.com/bug?extid=31eb4d4e7d9bc1fc1312
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=161cdfc0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12dfc8df980000
If the result looks correct, please mark the issue as fixed by replying with:
#syz fix: cgroup: change rstat function signatures from cgroup-based to css-based
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock
2025-06-01 16:21 ` syzbot
@ 2025-06-02 14:15 ` Michal Koutný
2025-06-17 10:00 ` Michal Koutný
0 siblings, 1 reply; 7+ messages in thread
From: Michal Koutný @ 2025-06-02 14:15 UTC (permalink / raw)
To: syzbot, inwardvessel
Cc: akpm, andrii, ast, axboe, bpf, cgroups, daniel, eddyz87, hannes,
haoluo, hawk, john.fastabend, jolsa, josef, kpsingh, linux-block,
linux-kernel, linux-kselftest, linux-mm, martin.lau, mhocko,
muchun.song, mykolal, netdev, roman.gushchin, sdf, shakeel.butt,
shuah, song, syzkaller-bugs, tj, yonghong.song
[-- Attachment #1: Type: text/plain, Size: 882 bytes --]
On Sun, Jun 01, 2025 at 09:21:02AM -0700, syzbot <syzbot+31eb4d4e7d9bc1fc1312@syzkaller.appspotmail.com> wrote:
> syzbot suspects this issue was fixed by commit:
>
> commit a97915559f5c5ff1972d678b94fd460c72a3b5f2
> Author: JP Kobryn <inwardvessel@gmail.com>
> Date: Fri Apr 4 01:10:48 2025 +0000
>
> cgroup: change rstat function signatures from cgroup-based to css-based
It says: "This non-functional change serves..."
However, it moves the *_rstat_init in cgroup_create() after kernfs dir
creation and given the reproducer has a fault injected:
mkdir(&(0x7f0000000000)='./cgroup/file0\x00', 0xd0939199c36b4d28) (fail_nth: 8)
I'd say this might be relevant (although I don't see the possibly
incorrect error handlnig path) but it doesn't mean this commit fixes it,
it'd rather require the reproducer to adjust the N on this path.
0.02€,
Michal
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock
2025-06-02 14:15 ` Michal Koutný
@ 2025-06-17 10:00 ` Michal Koutný
0 siblings, 0 replies; 7+ messages in thread
From: Michal Koutný @ 2025-06-17 10:00 UTC (permalink / raw)
To: syzbot, inwardvessel
Cc: akpm, andrii, ast, axboe, bpf, cgroups, daniel, eddyz87, hannes,
haoluo, hawk, john.fastabend, jolsa, josef, kpsingh, linux-block,
linux-kernel, linux-kselftest, linux-mm, martin.lau, mhocko,
muchun.song, mykolal, netdev, roman.gushchin, sdf, shakeel.butt,
shuah, song, syzkaller-bugs, tj, yonghong.song
[-- Attachment #1: Type: text/plain, Size: 680 bytes --]
On Mon, Jun 02, 2025 at 04:15:56PM +0200, Michal Koutný <mkoutny@suse.com> wrote:
> I'd say this might be relevant (although I don't see the possibly
> incorrect error handlnig path) but it doesn't mean this commit fixes it,
> it'd rather require the reproducer to adjust the N on this path.
Hm, possibly syzbot caught up here [1]:
-mkdir(&(0x7f0000000000)='./cgroup/file0\x00', 0xd0939199c36b4d28) (fail_nth: 8)
+mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f00000005c0)='./cgroup.net/syz0\x00', 0x1ff) (fail_nth: 23)
So there's something fishy in the error handling.
HTH,
Michal
[1] https://lore.kernel.org/lkml/68403875.a00a0220.d4325.000a.GAE@google.com/
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^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2025-06-17 10:00 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-12-05 17:48 [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock syzbot
2024-12-11 19:52 ` Tejun Heo
2024-12-11 20:21 ` syzbot
2024-12-11 20:48 ` Tejun Heo
2025-06-01 16:21 ` syzbot
2025-06-02 14:15 ` Michal Koutný
2025-06-17 10:00 ` Michal Koutný
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