libbacktrace: fix UBSAN issues
Commit Message
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
Ready to be installed?
Thanks,
Martin
Fix issues mentioned in the PR.
PR libbacktrace/103167
libbacktrace/ChangeLog:
* elf.c (elf_uncompress_lzma_block): Cast to unsigned int.
(elf_uncompress_lzma): Likewise.
* xztest.c (test_samples): memcpy only if v > 0.
Co-Authored-By: Andrew Pinski <apinski@marvell.com>
---
libbacktrace/elf.c | 8 ++++----
libbacktrace/xztest.c | 2 +-
2 files changed, 5 insertions(+), 5 deletions(-)
Comments
On Thu, Nov 11, 2021 at 7:39 AM Martin Liška <mliska@suse.cz> wrote:
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?
> Thanks,
> Martin
>
> Fix issues mentioned in the PR.
>
> PR libbacktrace/103167
>
> libbacktrace/ChangeLog:
>
> * elf.c (elf_uncompress_lzma_block): Cast to unsigned int.
> (elf_uncompress_lzma): Likewise.
> * xztest.c (test_samples): memcpy only if v > 0.
>
> Co-Authored-By: Andrew Pinski <apinski@marvell.com>
> ---
> libbacktrace/elf.c | 8 ++++----
> libbacktrace/xztest.c | 2 +-
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/libbacktrace/elf.c b/libbacktrace/elf.c
> index 79d56146fc6..e69ac41c88b 100644
> --- a/libbacktrace/elf.c
> +++ b/libbacktrace/elf.c
> @@ -3175,7 +3175,7 @@ elf_uncompress_lzma_block (const unsigned char *compressed,
> stream_crc = (compressed[off]
> | (compressed[off + 1] << 8)
> | (compressed[off + 2] << 16)
> - | (compressed[off + 3] << 24));
> + | ((unsigned)(compressed[off + 3]) << 24));
Thanks, but this kind of thing looks strange and is therefore likely
to break again in the future. I suggest instead
stream_crc = ((uint32_t) compressed[off]
| ((uint32_t) compressed[off + 1] << 8)
| ((uint32_t) compressed[off + 2] << 16)
| ((uint32_t) compressed[off + 3] << 24));
Same for the similar cases elsewhere.
Ian
On 11/11/21 20:21, Ian Lance Taylor wrote:
> On Thu, Nov 11, 2021 at 7:39 AM Martin Liška <mliska@suse.cz> wrote:
>>
>> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>>
>> Ready to be installed?
>> Thanks,
>> Martin
>>
>> Fix issues mentioned in the PR.
>>
>> PR libbacktrace/103167
>>
>> libbacktrace/ChangeLog:
>>
>> * elf.c (elf_uncompress_lzma_block): Cast to unsigned int.
>> (elf_uncompress_lzma): Likewise.
>> * xztest.c (test_samples): memcpy only if v > 0.
>>
>> Co-Authored-By: Andrew Pinski <apinski@marvell.com>
>> ---
>> libbacktrace/elf.c | 8 ++++----
>> libbacktrace/xztest.c | 2 +-
>> 2 files changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/libbacktrace/elf.c b/libbacktrace/elf.c
>> index 79d56146fc6..e69ac41c88b 100644
>> --- a/libbacktrace/elf.c
>> +++ b/libbacktrace/elf.c
>> @@ -3175,7 +3175,7 @@ elf_uncompress_lzma_block (const unsigned char *compressed,
>> stream_crc = (compressed[off]
>> | (compressed[off + 1] << 8)
>> | (compressed[off + 2] << 16)
>> - | (compressed[off + 3] << 24));
>> + | ((unsigned)(compressed[off + 3]) << 24));
>
> Thanks, but this kind of thing looks strange and is therefore likely
> to break again in the future. I suggest instead
>
> stream_crc = ((uint32_t) compressed[off]
> | ((uint32_t) compressed[off + 1] << 8)
> | ((uint32_t) compressed[off + 2] << 16)
> | ((uint32_t) compressed[off + 3] << 24));
>
> Same for the similar cases elsewhere.
Sure, done and pushed as g:83310a08a2bc52b6e8c3a3e3216b4e723e58c961.
Thanks,
Martin
>
> Ian
>
@@ -3175,7 +3175,7 @@ elf_uncompress_lzma_block (const unsigned char *compressed,
stream_crc = (compressed[off]
| (compressed[off + 1] << 8)
| (compressed[off + 2] << 16)
- | (compressed[off + 3] << 24));
+ | ((unsigned)(compressed[off + 3]) << 24));
if (unlikely (computed_crc != stream_crc))
{
elf_uncompress_failed ();
@@ -3788,7 +3788,7 @@ elf_uncompress_lzma (struct backtrace_state *state,
stream_crc = (compressed[8]
| (compressed[9] << 8)
| (compressed[10] << 16)
- | (compressed[11] << 24));
+ | ((unsigned)(compressed[11]) << 24));
if (unlikely (computed_crc != stream_crc))
{
elf_uncompress_failed ();
@@ -3832,7 +3832,7 @@ elf_uncompress_lzma (struct backtrace_state *state,
stream_crc = (compressed[offset - 4]
| (compressed[offset - 3] << 8)
| (compressed[offset - 2] << 16)
- | (compressed[offset - 1] << 24));
+ | ((unsigned)(compressed[offset - 1]) << 24));
if (unlikely (computed_crc != stream_crc))
{
elf_uncompress_failed ();
@@ -3891,7 +3891,7 @@ elf_uncompress_lzma (struct backtrace_state *state,
stream_crc = (compressed[offset]
| (compressed[offset + 1] << 8)
| (compressed[offset + 2] << 16)
- | (compressed[offset + 3] << 24));
+ | ((unsigned)(compressed[offset + 3]) << 24));
if (unlikely (computed_crc != stream_crc))
{
elf_uncompress_failed ();
@@ -172,7 +172,7 @@ test_samples (struct backtrace_state *state)
tests[i].name, uncompressed_len, v);
++failures;
}
- else if (memcmp (tests[i].uncompressed, uncompressed, v) != 0)
+ else if (v > 0 && memcmp (tests[i].uncompressed, uncompressed, v) != 0)
{
size_t j;