Following error occurs when trying to use 'perf report' on x86_64 to
cross analysis a perf.data generated by an old perf on a big-endian
machine:
# perf report
*** Error in `/home/w00229757/perf': free(): invalid next size (fast):
0x00000000032c99f0 ***
======= Backtrace: =========
/lib64/libc.so.6(+0x6eeef)[0x7ff6ff7e2eef]
/lib64/libc.so.6(+0x78cae)[0x7ff6ff7eccae]
/lib64/libc.so.6(+0x79987)[0x7ff6ff7ed987]
/path/to/perf[0x4ac734]
/path/to/perf[0x4ac829]
/path/to/perf(perf_header__process_sections+0x129)[0x4ad2c9]
/path/to/perf(perf_session__read_header+0x2e1)[0x4ad9e1]
/path/to/perf(perf_session__new+0x168)[0x4bd458]
/path/to/perf(cmd_report+0xfa0)[0x43eb70]
/path/to/perf[0x47adc3]
/path/to/perf(main+0x5f6)[0x42fd06]
/lib64/libc.so.6(__libc_start_main+0xf5)[0x7ff6ff795bd5]
/path/to/perf[0x42fe35]
======= Memory map: ========
[SNIP]
The bug is in perf_event__attr_swap(). It swaps all fields in
'struct perf_event_attr' without checking whether the swapped field
exist or not. In addition, in read_event_desc() allocs memory for attr
according to size read from perf.data. Therefore, if the perf.data is
collected by an old perf (without aux_watermark, for example),
when perf_event__attr_swap() swaping attr->aux_watermark it destroy
malloc's metadata.
This patch introduces boundary checking in perf_event__attr_swap(). It
adds macros bswap_field_64 and bswap_field_32 into
perf_event__attr_swap() to make it only swap exist fields.
Signed-off-by: Wang Nan <wangn...@huawei.com>
---
tools/perf/util/session.c | 40 ++++++++++++++++++++++++++--------------
1 file changed, 26 insertions(+), 14 deletions(-)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 88d87bf..d51ba31 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -517,20 +517,32 @@ void perf_event__attr_swap(struct perf_event_attr *attr)
{
attr->type = bswap_32(attr->type);
attr->size = bswap_32(attr->size);
- attr->config = bswap_64(attr->config);
- attr->sample_period = bswap_64(attr->sample_period);
- attr->sample_type = bswap_64(attr->sample_type);
- attr->read_format = bswap_64(attr->read_format);
- attr->wakeup_events = bswap_32(attr->wakeup_events);
- attr->bp_type = bswap_32(attr->bp_type);
- attr->bp_addr = bswap_64(attr->bp_addr);
- attr->bp_len = bswap_64(attr->bp_len);
- attr->branch_sample_type = bswap_64(attr->branch_sample_type);
- attr->sample_regs_user = bswap_64(attr->sample_regs_user);
- attr->sample_stack_user = bswap_32(attr->sample_stack_user);
- attr->aux_watermark = bswap_32(attr->aux_watermark);
-
- swap_bitfield((u8 *) (&attr->read_format + 1), sizeof(u64));
+#define bswap_safe(f) \
+ (attr->size > offsetof(struct perf_event_attr, f))
+#define bswap_field(f, sz) \
+do { \
+ if (bswap_safe(f)) \
+ attr->f = bswap_##sz(attr->f); \
+} while(0)
+#define bswap_field_32(f) bswap_field(f, 32)
+#define bswap_field_64(f) bswap_field(f, 64)
+
+ bswap_field_64(config);
+ bswap_field_64(sample_period);
+ bswap_field_64(sample_type);
+ bswap_field_64(read_format);
+ bswap_field_32(wakeup_events);
+ bswap_field_32(bp_type);
+ bswap_field_64(bp_addr);
+ bswap_field_64(bp_len);
+ bswap_field_64(branch_sample_type);
+ bswap_field_64(sample_regs_user);
+ bswap_field_32(sample_stack_user);
+ bswap_field_32(aux_watermark);
+
+ if (bswap_safe(read_format))
+ swap_bitfield((u8 *) (&attr->read_format + 1),
+ sizeof(u64));
}
static void perf_event__hdr_attr_swap(union perf_event *event,
--
1.8.3.4
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