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| author | Nick Alcock <nick.alcock@oracle.com> | 2021-03-25 16:32:46 +0000 |
|---|---|---|
| committer | Nick Alcock <nick.alcock@oracle.com> | 2021-03-25 16:32:48 +0000 |
| commit | 86f64bf43f70ecefa9232f5b8621b179dfff52fd (patch) | |
| tree | a5bdee1f432ebdbe78db8a65e6d0133907c9c9a5 /libctf | |
| parent | 24c877f9b19dc38f9c40e25116175481c8bb78f2 (diff) | |
| download | gdb-86f64bf43f70ecefa9232f5b8621b179dfff52fd.zip gdb-86f64bf43f70ecefa9232f5b8621b179dfff52fd.tar.gz gdb-86f64bf43f70ecefa9232f5b8621b179dfff52fd.tar.bz2 | |
libctf, serialize: functions with no args have a NULL dtd_vlen
Every place that accesses a function's dtd_vlen accesses it only if the
number of args is nonzero, except the serializer, which always tries to
memcpy it. The number of bytes it memcpys in this case is zero, but it
is still undefined behaviour to copy zero bytes from a null pointer.
So check for this case explicitly.
libctf/ChangeLog
2021-03-25 Nick Alcock <nick.alcock@oracle.com>
PR libctf/27628
* ctf-serialize.c (ctf_emit_type_sect): Allow for a NULL vlen in
CTF_K_FUNCTION types.
Diffstat (limited to 'libctf')
| -rw-r--r-- | libctf/ChangeLog | 6 | ||||
| -rw-r--r-- | libctf/ctf-serialize.c | 4 |
2 files changed, 9 insertions, 1 deletions
diff --git a/libctf/ChangeLog b/libctf/ChangeLog index 909c4fc..a9e76ec 100644 --- a/libctf/ChangeLog +++ b/libctf/ChangeLog @@ -1,5 +1,11 @@ 2021-03-25 Nick Alcock <nick.alcock@oracle.com> + PR libctf/27628 + * ctf-serialize.c (ctf_emit_type_sect): Allow for a NULL vlen in + CTF_K_FUNCTION types. + +2021-03-25 Nick Alcock <nick.alcock@oracle.com> + * ctf-dump.c (ctf_dump_format_type): Don't emit size or alignment on error. diff --git a/libctf/ctf-serialize.c b/libctf/ctf-serialize.c index 0811b7b..9f50280 100644 --- a/libctf/ctf-serialize.c +++ b/libctf/ctf-serialize.c @@ -849,7 +849,9 @@ ctf_emit_type_sect (ctf_dict_t *fp, unsigned char **tptr) break; case CTF_K_FUNCTION: - memcpy (t, dtd->dtd_vlen, sizeof (uint32_t) * (vlen + (vlen & 1))); + /* Functions with no args also have no vlen. */ + if (dtd->dtd_vlen) + memcpy (t, dtd->dtd_vlen, sizeof (uint32_t) * (vlen + (vlen & 1))); t += sizeof (uint32_t) * (vlen + (vlen & 1)); break; |