public inbox for glibc-cvs@sourceware.org help / color / mirror / Atom feed
From: Florian Weimer <fw@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/release/2.25/master] libio: Disable vtable validation in case of interposition [BZ #23313] Date: Thu, 28 Nov 2019 16:48:00 -0000 [thread overview] Message-ID: <20191128164854.46145.qmail@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=8440c51d8981e8e40d611a2cbf9850091e7d5a72 commit 8440c51d8981e8e40d611a2cbf9850091e7d5a72 Author: Florian Weimer <fweimer@redhat.com> Date: Tue Jun 26 10:24:52 2018 +0200 libio: Disable vtable validation in case of interposition [BZ #23313] (cherry picked from commit c402355dfa7807b8e0adb27c009135a7e2b9f1b0) Diff: --- ChangeLog | 5 +++++ libio/vtables.c | 16 ++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/ChangeLog b/ChangeLog index 9a8840b..94788a9 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. + 2019-11-01 Dragan Mladjenovic <dmladjenovic@wavecomp.com> * sysdeps/unix/sysv/linux/mips/Makefile diff --git a/libio/vtables.c b/libio/vtables.c index 41b48db..a11226a 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
reply other threads:[~2019-11-28 16:48 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20191128164854.46145.qmail@sourceware.org \ --to=fw@sourceware.org \ --cc=glibc-cvs@sourceware.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).