Date:   Wed, 15 Mar 2023 21:01:26 -0000
From:   "tip-bot2 for Yang Jihong" <tip-bot2@linutronix.de>
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To:     linux-tip-commits@vger.kernel.org
Subject: [tip: perf/urgent] perf/core: Fix perf_output_begin parameter is
 incorrectly invoked in perf_event_bpf_output
Cc:     Yang Jihong <yangjihong1@huawei.com>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>, x86@kernel.org,
        linux-kernel@vger.kernel.org
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The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     eb81a2ed4f52be831c9fb879752d89645a312c13
Gitweb:        https://git.kernel.org/tip/eb81a2ed4f52be831c9fb879752d89645a312c13
Author:        Yang Jihong <yangjihong1@huawei.com>
AuthorDate:    Tue, 14 Mar 2023 04:47:35 
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 15 Mar 2023 21:49:46 +01:00

perf/core: Fix perf_output_begin parameter is incorrectly invoked in perf_event_bpf_output

syzkaller reportes a KASAN issue with stack-out-of-bounds.
The call trace is as follows:
  dump_stack+0x9c/0xd3
  print_address_description.constprop.0+0x19/0x170
  __kasan_report.cold+0x6c/0x84
  kasan_report+0x3a/0x50
  __perf_event_header__init_id+0x34/0x290
  perf_event_header__init_id+0x48/0x60
  perf_output_begin+0x4a4/0x560
  perf_event_bpf_output+0x161/0x1e0
  perf_iterate_sb_cpu+0x29e/0x340
  perf_iterate_sb+0x4c/0xc0
  perf_event_bpf_event+0x194/0x2c0
  __bpf_prog_put.constprop.0+0x55/0xf0
  __cls_bpf_delete_prog+0xea/0x120 [cls_bpf]
  cls_bpf_delete_prog_work+0x1c/0x30 [cls_bpf]
  process_one_work+0x3c2/0x730
  worker_thread+0x93/0x650
  kthread+0x1b8/0x210
  ret_from_fork+0x1f/0x30

commit 267fb27352b6 ("perf: Reduce stack usage of perf_output_begin()")
use on-stack struct perf_sample_data of the caller function.

However, perf_event_bpf_output uses incorrect parameter to convert
small-sized data (struct perf_bpf_event) into large-sized data
(struct perf_sample_data), which causes memory overwriting occurs in
__perf_event_header__init_id.

Fixes: 267fb27352b6 ("perf: Reduce stack usage of perf_output_begin()")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230314044735.56551-1-yangjihong1@huawei.com
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f79fd8b..296617e 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9187,7 +9187,7 @@ static void perf_event_bpf_output(struct perf_event *event, void *data)
 
 	perf_event_header__init_id(&bpf_event->event_id.header,
 				   &sample, event);
-	ret = perf_output_begin(&handle, data, event,
+	ret = perf_output_begin(&handle, &sample, event,
 				bpf_event->event_id.header.size);
 	if (ret)
 		return;