kprobes: Prohibit probes in gate area
The system call gate area counts as kernel text but trying
to install a kprobe in this area fails with an Oops later on.
To fix this explicitly disallow the gate area for kprobes.
Found by syzkaller with the following reproducer:
perf_event_open$cgroup(&(0x7f00000001c0)={0x6, 0x80, 0x0, 0x0, 0x0, 0x0, 0x80ffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @perf_config_ext={0x0, 0xffffffffff600000}}, 0xffffffffffffffff, 0x0, 0xffffffffffffffff, 0x0)
Sample report:
BUG: unable to handle page fault for address:
fffffbfff3ac6000
PGD
6dfcb067 P4D
6dfcb067 PUD
6df8f067 PMD
6de4d067 PTE 0
Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 PID: 21978 Comm: syz-executor.2 Not tainted
6.0.0-rc3-00363-g7726d4c3e60b-dirty #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:__insn_get_emulate_prefix arch/x86/lib/insn.c:91 [inline]
RIP: 0010:insn_get_emulate_prefix arch/x86/lib/insn.c:106 [inline]
RIP: 0010:insn_get_prefixes.part.0+0xa8/0x1110 arch/x86/lib/insn.c:134
Code: 49 be 00 00 00 00 00 fc ff df 48 8b 40 60 48 89 44 24 08 e9 81 00 00 00 e8 e5 4b 39 ff 4c 89 fa 4c 89 f9 48 c1 ea 03 83 e1 07 <42> 0f b6 14 32 38 ca 7f 08 84 d2 0f 85 06 10 00 00 48 89 d8 48 89
RSP: 0018:
ffffc900088bf860 EFLAGS:
00010246
RAX:
0000000000040000 RBX:
ffffffff9b9bebc0 RCX:
0000000000000000
RDX:
1ffffffff3ac6000 RSI:
ffffc90002d82000 RDI:
ffffc900088bf9e8
RBP:
ffffffff9d630001 R08:
0000000000000000 R09:
ffffc900088bf9e8
R10:
0000000000000000 R11:
0000000000000001 R12:
0000000000000001
R13:
ffffffff9d630000 R14:
dffffc0000000000 R15:
ffffffff9d630000
FS:
00007f63eef63640(0000) GS:
ffff88806d000000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
fffffbfff3ac6000 CR3:
0000000029d90005 CR4:
0000000000770ef0
PKRU:
55555554
Call Trace:
<TASK>
insn_get_prefixes arch/x86/lib/insn.c:131 [inline]
insn_get_opcode arch/x86/lib/insn.c:272 [inline]
insn_get_modrm+0x64a/0x7b0 arch/x86/lib/insn.c:343
insn_get_sib+0x29a/0x330 arch/x86/lib/insn.c:421
insn_get_displacement+0x350/0x6b0 arch/x86/lib/insn.c:464
insn_get_immediate arch/x86/lib/insn.c:632 [inline]
insn_get_length arch/x86/lib/insn.c:707 [inline]
insn_decode+0x43a/0x490 arch/x86/lib/insn.c:747
can_probe+0xfc/0x1d0 arch/x86/kernel/kprobes/core.c:282
arch_prepare_kprobe+0x79/0x1c0 arch/x86/kernel/kprobes/core.c:739
prepare_kprobe kernel/kprobes.c:1160 [inline]
register_kprobe kernel/kprobes.c:1641 [inline]
register_kprobe+0xb6e/0x1690 kernel/kprobes.c:1603
__register_trace_kprobe kernel/trace/trace_kprobe.c:509 [inline]
__register_trace_kprobe+0x26a/0x2d0 kernel/trace/trace_kprobe.c:477
create_local_trace_kprobe+0x1f7/0x350 kernel/trace/trace_kprobe.c:1833
perf_kprobe_init+0x18c/0x280 kernel/trace/trace_event_perf.c:271
perf_kprobe_event_init+0xf8/0x1c0 kernel/events/core.c:9888
perf_try_init_event+0x12d/0x570 kernel/events/core.c:11261
perf_init_event kernel/events/core.c:11325 [inline]
perf_event_alloc.part.0+0xf7f/0x36a0 kernel/events/core.c:11619
perf_event_alloc kernel/events/core.c:12059 [inline]
__do_sys_perf_event_open+0x4a8/0x2a00 kernel/events/core.c:12157
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f63ef7efaed
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:
00007f63eef63028 EFLAGS:
00000246 ORIG_RAX:
000000000000012a
RAX:
ffffffffffffffda RBX:
00007f63ef90ff80 RCX:
00007f63ef7efaed
RDX:
0000000000000000 RSI:
ffffffffffffffff RDI:
00000000200001c0
RBP:
00007f63ef86019c R08:
0000000000000000 R09:
0000000000000000
R10:
ffffffffffffffff R11:
0000000000000246 R12:
0000000000000000
R13:
0000000000000002 R14:
00007f63ef90ff80 R15:
00007f63eef43000
</TASK>
Modules linked in:
CR2:
fffffbfff3ac6000
---[ end trace
0000000000000000 ]---
RIP: 0010:__insn_get_emulate_prefix arch/x86/lib/insn.c:91 [inline]
RIP: 0010:insn_get_emulate_prefix arch/x86/lib/insn.c:106 [inline]
RIP: 0010:insn_get_prefixes.part.0+0xa8/0x1110 arch/x86/lib/insn.c:134
Code: 49 be 00 00 00 00 00 fc ff df 48 8b 40 60 48 89 44 24 08 e9 81 00 00 00 e8 e5 4b 39 ff 4c 89 fa 4c 89 f9 48 c1 ea 03 83 e1 07 <42> 0f b6 14 32 38 ca 7f 08 84 d2 0f 85 06 10 00 00 48 89 d8 48 89
RSP: 0018:
ffffc900088bf860 EFLAGS:
00010246
RAX:
0000000000040000 RBX:
ffffffff9b9bebc0 RCX:
0000000000000000
RDX:
1ffffffff3ac6000 RSI:
ffffc90002d82000 RDI:
ffffc900088bf9e8
RBP:
ffffffff9d630001 R08:
0000000000000000 R09:
ffffc900088bf9e8
R10:
0000000000000000 R11:
0000000000000001 R12:
0000000000000001
R13:
ffffffff9d630000 R14:
dffffc0000000000 R15:
ffffffff9d630000
FS:
00007f63eef63640(0000) GS:
ffff88806d000000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
fffffbfff3ac6000 CR3:
0000000029d90005 CR4:
0000000000770ef0
PKRU:
55555554
==================================================================
Link: https://lkml.kernel.org/r/20220907200917.654103-1-lk@c--e.de
cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
cc: "David S. Miller" <davem@davemloft.net>
Cc: stable@vger.kernel.org
Fixes:
1da177e4c3f4 ("Linux-2.6.12-rc2")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>