Re: /usr/bin/ftp crash on -current (10.00.4) aarch64

[Chavdar Ivanov <ci4ic4%gmail.com@localhost>]

On Thu, 18 May 2023 at 13:16, RVP <rvp%sdf.org@localhost> wrote:
>
> On Thu, 18 May 2023, Chavdar Ivanov wrote:
>
> > Yes indeed, with SIGILL passed I get:
> >
> >
> > Program received signal SIGSEGV, Segmentation fault.
> > 0x0000f03114c97890 in EC_GROUP_order_bits () from /usr/lib/libcrypto.so.14
> > (gdb) bt
> > #0  0x0000f03114c97890 in EC_GROUP_order_bits () from /usr/lib/libcrypto.so.14
> > #1  0x0000f031154898a4 in engine_unlocked_init () from /usr/lib/libcrypto.so.15
> > #2  0x0000f03115489ab0 in ENGINE_init () from /usr/lib/libcrypto.so.15
> > #3  0x0000f031153d11f0 in ?? () from /usr/lib/libcrypto.so.15
> > #4  0x0000f03115694c30 in ssl_setup_sig_algs () from /usr/lib/libssl.so.15
> > #5  0x0000f031156a85c4 in SSL_CTX_new_ex () from /usr/lib/libssl.so.15
> > #6  0x000000000f1be6d8 in fetch_start_ssl ()
> > #7  0x000000000f1b0dfc in fetch_url ()
> > #8  0x000000000f1b3128 in auto_fetch ()
> > #9  0x000000000f1bf944 in main ()
> >
>
> You can see the cause right in that stack trace:
>
> EC_GROUP_order_bits is from libcrypto.so.14, but,
> engine_unlocked_init etc., are from libcrypto.so.15
>
> This is our old friend: library interpositioning and it happens due to
> this:
>
> $ readelf -d /mnt/usr/bin/ftp | f NEEDED
>   0x0000000000000001 NEEDED               Shared library: [libedit.so.3]
>   0x0000000000000001 NEEDED               Shared library: [libterminfo.so.2]
>   0x0000000000000001 NEEDED               Shared library: [libssl.so.14]
>   0x0000000000000001 NEEDED               Shared library: [libcrypto.so.14]
>   0x0000000000000001 NEEDED               Shared library: [libc.so.12]
> $ readelf -d /mnt/usr/lib/libssl.so.14 | f NEEDED
>   0x0000000000000001 NEEDED               Shared library: [libcrypto.so.14]
>   0x0000000000000001 NEEDED               Shared library: [libc.so.12]
>
>
> So, my ftp binary explicitly needs `libcrypto.so.14'. and `libssl' also has
> _the same version_ as a dependency. But, in your case, the ftp binary will
> show `libcrypto.so.15', but libssl will need `libcrypto.so.14'. Ie. the
> compiler linked in the newer version explicitly (cc ... -lcrypto') and the
> other one was brought in implicitly via libssl.

Indeed:

# readelf -d /usr/bin/ftp | grep NEEDED
 0x0000000000000001 (NEEDED)             Shared library: [libedit.so.3]
 0x0000000000000001 (NEEDED)             Shared library: [libterminfo.so.2]
 0x0000000000000001 (NEEDED)             Shared library: [libssl.so.15]
 0x0000000000000001 (NEEDED)             Shared library: [libcrypto.so.15]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.12]
# readelf -d /usr/lib/libssl.so.15.0 | grep NEEDED
 0x0000000000000001 (NEEDED)             Shared library: [libcrypto.so.14]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.12]

Rebuilding clean now.

Thanks,

Chavdar

>
> -RVP
>


-- 
----