[syzbot] [trace?] general protection fault in mtree_load

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 6b5a2b7d9bc1 Merge tag 'trace-tools-v7.2' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16d56986580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ea6584355d75e0cd
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

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-6b5a2b7d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b3cb0499fbe9/vmlinux-6b5a2b7d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/47cfbe57f6ea/bzImage-6b5a2b7d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+61ce80...@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: 24402 Comm: syz.4.5217 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
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 6b bd 84 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 6f 1a 08 00 31 ff
RSP: 0018:ffffc900039c76d8 EFLAGS: 00010206
RAX: 0000000000000011 RBX: 0000000000000040 RCX: ffffffff8b848746
RDX: ffff888041b6a540 RSI: ffffffff8b848775 RDI: 0000000000000088
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 000000000000751b R12: dffffc0000000000
R13: ffff88802693adc0 R14: 00001fff904365a7 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880d665f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f44aa04f156 CR3: 00000000364d5000 CR4: 0000000000352ef0
Call Trace:
<TASK>
vma_lookup include/linux/mm.h:4204 [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:2936 [inline]
bpf_uprobe_multi_link_release+0xb3/0x1c0 kernel/trace/bpf_trace.c:2947
bpf_link_free+0xec/0x4a0 kernel/bpf/syscall.c:3273
bpf_link_put_direct kernel/bpf/syscall.c:3326 [inline]
bpf_link_release+0x5d/0x80 kernel/bpf/syscall.c:3333
__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]
ret_from_fork+0x932/0xd50 arch/x86/kernel/process.c:167
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</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 6b bd 84 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 6f 1a 08 00 31 ff
RSP: 0018:ffffc900039c76d8 EFLAGS: 00010206
RAX: 0000000000000011 RBX: 0000000000000040 RCX: ffffffff8b848746
RDX: ffff888041b6a540 RSI: ffffffff8b848775 RDI: 0000000000000088
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 000000000000751b R12: dffffc0000000000
R13: ffff88802693adc0 R14: 00001fff904365a7 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880d665f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c433cbf CR3: 00000000429b6000 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 6b bd 84 f6 call 0xf684bd7d
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 6f 1a 08 00 call 0x81aad
3e: 31 ff xor %edi,%edi


---
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[Oleg Nesterov]

current->mm is already NULL, the exiting task has already passed exit_mm().

Hopefully

[PATCHv4 01/13] uprobes/x86: Use proper mm_struct in __in_uprobe_trampoline
https://lore.kernel.org/all/20260526205840...@kernel.org/

should help...

Oleg.

[Jiri Olsa]

yes, that sould fix it

thanks,
jirka

[syzbot]

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+61ce80...@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


---

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