From: syzbot <syzbot+61ce80689253f42e6d80@syzkaller.appspotmail.com>
To: bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com,
linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org, mhiramat@kernel.org,
mingo@redhat.com, oleg@redhat.com, olsajiri@gmail.com,
peterz@infradead.org, syzkaller-bugs@googlegroups.com,
tglx@kernel.org, x86@kernel.org
Subject: Re: [syzbot] [trace?] general protection fault in mtree_load
Date: Tue, 30 Jun 2026 18:32:24 -0700 [thread overview]
Message-ID: <6a446e28.854d4ab9.360e1d.0017.GAE@google.com> (raw)
In-Reply-To: <6a38dd47.713c5d62.148f7.000c.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: dc59e4fea9d8 Linux 7.2-rc1
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15c7d61c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f9bf5d2bfae96234
dashboard link: https://syzkaller.appspot.com/bug?extid=61ce80689253f42e6d80
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12bbb11c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=130bf4ea580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-dc59e4fe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1bc8aed8d2e8/vmlinux-dc59e4fe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0b1fdfc4aa09/bzImage-dc59e4fe.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+61ce80689253f42e6d80@syzkaller.appspotmail.com
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
CPU: 3 UID: 0 PID: 6107 Comm: syz.0.85 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:mas_root lib/maple_tree.c:759 [inline]
RIP: 0010:mas_start lib/maple_tree.c:1179 [inline]
RIP: 0010:mtree_load+0x16d/0xa90 lib/maple_tree.c:5657
Code: 00 00 00 00 48 c7 44 24 78 ff ff ff ff e8 5b c8 74 f6 48 8b 5c 24 50 c6 84 24 9c 00 00 00 00 48 8d 7b 48 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 d6 08 00 00 48 8b 5b 48 e8 3f 1a 08 00 31 ff
RSP: 0018:ffffc9000412f740 EFLAGS: 00010206
RAX: 0000000000000011 RBX: 0000000000000040 RCX: ffffffff8b94b796
RDX: ffff888035462540 RSI: ffffffff8b94b7c5 RDI: 0000000000000088
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888013522280 R14: 0000200000ffc007 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880d63e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8aaa4cff8 CR3: 0000000038832000 CR4: 0000000000352ef0
Call Trace:
<TASK>
vma_lookup include/linux/mm.h:4238 [inline]
__in_uprobe_trampoline arch/x86/kernel/uprobes.c:766 [inline]
__is_optimized arch/x86/kernel/uprobes.c:1056 [inline]
is_optimized arch/x86/kernel/uprobes.c:1067 [inline]
set_orig_insn+0x1ec/0x2a0 arch/x86/kernel/uprobes.c:1098
remove_breakpoint kernel/events/uprobes.c:1185 [inline]
register_for_each_vma+0xbb7/0xdb0 kernel/events/uprobes.c:1318
uprobe_unregister_nosync+0x12a/0x1c0 kernel/events/uprobes.c:1343
bpf_uprobe_unregister kernel/trace/bpf_trace.c:2982 [inline]
bpf_uprobe_multi_link_release+0xb3/0x1c0 kernel/trace/bpf_trace.c:2993
bpf_link_free+0xec/0x4a0 kernel/bpf/syscall.c:3395
bpf_link_put_direct kernel/bpf/syscall.c:3448 [inline]
bpf_link_release+0x5d/0x80 kernel/bpf/syscall.c:3455
__fput+0x3ff/0xb50 fs/file_table.c:512
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x951/0x2ae0 kernel/exit.c:1004
do_group_exit+0xd5/0x2a0 kernel/exit.c:1147
get_signal+0x1ec7/0x21e0 kernel/signal.c:3038
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc8a9b9de59
Code: Unable to access opcode bytes at 0x7fc8a9b9de2f.
RSP: 002b:00007fc8aaa4d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fc8a9e25fa8 RCX: 00007fc8a9b9de59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc8a9e25fa8
RBP: 00007fc8a9e25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc8a9e26038 R14: 00007fff99db45c0 R15: 00007fff99db46a8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:mas_root lib/maple_tree.c:759 [inline]
RIP: 0010:mas_start lib/maple_tree.c:1179 [inline]
RIP: 0010:mtree_load+0x16d/0xa90 lib/maple_tree.c:5657
Code: 00 00 00 00 48 c7 44 24 78 ff ff ff ff e8 5b c8 74 f6 48 8b 5c 24 50 c6 84 24 9c 00 00 00 00 48 8d 7b 48 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 d6 08 00 00 48 8b 5b 48 e8 3f 1a 08 00 31 ff
RSP: 0018:ffffc9000412f740 EFLAGS: 00010206
RAX: 0000000000000011 RBX: 0000000000000040 RCX: ffffffff8b94b796
RDX: ffff888035462540 RSI: ffffffff8b94b7c5 RDI: 0000000000000088
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888013522280 R14: 0000200000ffc007 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880d63e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8aaa4cff8 CR3: 0000000038832000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 48 c7 44 24 78 ff ff movq $0xffffffffffffffff,0x78(%rsp)
b: ff ff
d: e8 5b c8 74 f6 call 0xf674c86d
12: 48 8b 5c 24 50 mov 0x50(%rsp),%rbx
17: c6 84 24 9c 00 00 00 movb $0x0,0x9c(%rsp)
1e: 00
1f: 48 8d 7b 48 lea 0x48(%rbx),%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 0f 85 d6 08 00 00 jne 0x90b
35: 48 8b 5b 48 mov 0x48(%rbx),%rbx
39: e8 3f 1a 08 00 call 0x81a7d
3e: 31 ff xor %edi,%edi
---
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.
next prev parent reply other threads:[~2026-07-01 1:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-22 6:59 [syzbot] [trace?] general protection fault in mtree_load syzbot
2026-06-22 13:04 ` Oleg Nesterov
2026-06-24 7:49 ` Jiri Olsa
2026-07-01 1:32 ` syzbot [this message]
2026-07-01 9:09 ` Oleg Nesterov
2026-07-01 9:42 ` syzbot
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