2023-03-14 04:50:39

by Yang Jihong

[permalink] [raw]
Subject: [PATCH] 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 <[email protected]>
---
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 f79fd8b87f75..296617edbda1 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;
--
2.30.GIT



Subject: [tip: perf/urgent] perf/core: Fix perf_output_begin parameter is incorrectly invoked in perf_event_bpf_output

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 <[email protected]>
AuthorDate: Tue, 14 Mar 2023 04:47:35
Committer: Peter Zijlstra <[email protected]>
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 <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
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;