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| author | Florian Weimer <fweimer@redhat.com> | 2018-06-26 10:24:52 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2018-07-03 15:57:55 +0200 |
| commit | 2781bd5a8690b5f1553b655f947a35f1d3dd23d0 (patch) | |
| tree | 263470d62a00044bf5658fc3a409fcb8ee97fc19 | |
| parent | 74d16a57a3615fcf05e5c60cb5a8f25e8acf38b9 (diff) | |
| download | glibc-2781bd5a8690b5f1553b655f947a35f1d3dd23d0.tar.gz glibc-2781bd5a8690b5f1553b655f947a35f1d3dd23d0.tar.xz glibc-2781bd5a8690b5f1553b655f947a35f1d3dd23d0.zip | |
libio: Disable vtable validation in case of interposition [BZ #23313]
(cherry picked from commit c402355dfa7807b8e0adb27c009135a7e2b9f1b0)
| -rw-r--r-- | ChangeLog | 5 | ||||
| -rw-r--r-- | NEWS | 1 | ||||
| -rw-r--r-- | libio/vtables.c | 16 |
3 files changed, 22 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index 7ecc33e61d..f1880ebc37 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2018-06-26 Florian Weimer <fweimer@redhat.com> + + [BZ #23313] + * libio/vtables.c (check_stdfiles_vtables): New ELF constructor. + 2017-11-15 Steve Ellcey <sellcey@cavium.com> [BZ #22442] diff --git a/NEWS b/NEWS index 48d28e166a..5bcca538c6 100644 --- a/NEWS +++ b/NEWS @@ -144,6 +144,7 @@ The following bugs are resolved with this release: [23171] Fix parameter type in C++ version of iseqsig [23196] __mempcpy_avx512_no_vzeroupper mishandles large copies [23236] Harden function pointers in _IO_str_fields + [23313] libio: Disable vtable validation in case of interposition [23349] Various glibc headers no longer compatible with <linux/time.h> Version 2.26 diff --git a/libio/vtables.c b/libio/vtables.c index 41b48db98c..a11226ab17 100644 --- a/libio/vtables.c +++ b/libio/vtables.c @@ -70,3 +70,19 @@ _IO_vtable_check (void) __libc_fatal ("Fatal error: glibc detected an invalid stdio handle\n"); } + +/* Some variants of libstdc++ interpose _IO_2_1_stdin_ etc. and + install their own vtables directly, without calling _IO_init or + other functions. Detect this by looking at the vtables values + during startup, and disable vtable validation in this case. */ +#ifdef SHARED +__attribute__ ((constructor)) +static void +check_stdfiles_vtables (void) +{ + if (_IO_2_1_stdin_.vtable != &_IO_file_jumps + || _IO_2_1_stdout_.vtable != &_IO_file_jumps + || _IO_2_1_stderr_.vtable != &_IO_file_jumps) + IO_set_accept_foreign_vtables (&_IO_vtable_check); +} +#endif |