From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1791) id A7F7E3858404; Thu, 1 Jun 2023 17:49:09 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A7F7E3858404 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1685641749; bh=EdsUh6MTHeKHwTNhOvuQPH8gxtM1++D1Zq7opXYhOSE=; h=From:To:Subject:Date:From; b=p4TF1yPIHhEkEUFpAsGr91CqVWRRYdhtNJQkB6RW7ATEk3Iju1fKJEqxfbBkH/epO iEtkv+5/UdzOucH+bnywsgav1bXoqWUtbB7RGqAQRPNrqIl3agwGK1kPIsmXVXg8ru EIAsLJ/dpvcs1gqykmRp0b71q2YfgVPzDzemz64U= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Adhemerval Zanella To: glibc-cvs@sourceware.org Subject: [glibc] getsourcefilter: Get rid of alloca. X-Act-Checkin: glibc X-Git-Author: Joe Simmons-Talbott X-Git-Refname: refs/heads/master X-Git-Oldrev: 29e25f6f136182fb3756d51e03dea7c4d1919dd9 X-Git-Newrev: d1eaab5a7932cda190cbbfa657c684059b141c19 Message-Id: <20230601174909.A7F7E3858404@sourceware.org> Date: Thu, 1 Jun 2023 17:49:09 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=d1eaab5a7932cda190cbbfa657c684059b141c19 commit d1eaab5a7932cda190cbbfa657c684059b141c19 Author: Joe Simmons-Talbott Date: Tue May 30 14:13:40 2023 -0400 getsourcefilter: Get rid of alloca. Use a scratch_buffer rather than alloca to avoid potential stack overflows. Reviewed-by: Adhemerval Zanella Diff: --- sysdeps/unix/sysv/linux/getsourcefilter.c | 24 +++++++----------------- 1 file changed, 7 insertions(+), 17 deletions(-) diff --git a/sysdeps/unix/sysv/linux/getsourcefilter.c b/sysdeps/unix/sysv/linux/getsourcefilter.c index b9ba58c23a..461ad889a9 100644 --- a/sysdeps/unix/sysv/linux/getsourcefilter.c +++ b/sysdeps/unix/sysv/linux/getsourcefilter.c @@ -16,10 +16,10 @@ License along with the GNU C Library; if not, see . */ -#include #include #include #include +#include #include #include #include @@ -95,17 +95,12 @@ getsourcefilter (int s, uint32_t interface, const struct sockaddr *group, /* We have to create an struct ip_msfilter object which we can pass to the kernel. */ socklen_t needed = GROUP_FILTER_SIZE (*numsrc); - int use_alloca = __libc_use_alloca (needed); - struct group_filter *gf; - if (use_alloca) - gf = (struct group_filter *) alloca (needed); - else - { - gf = (struct group_filter *) malloc (needed); - if (gf == NULL) - return -1; - } + struct scratch_buffer buf; + scratch_buffer_init (&buf); + if (!scratch_buffer_set_array_size (&buf, 1, needed)) + return -1; + struct group_filter *gf = buf.data; gf->gf_interface = interface; memcpy (&gf->gf_group, group, grouplen); @@ -135,12 +130,7 @@ getsourcefilter (int s, uint32_t interface, const struct sockaddr *group, } } - if (! use_alloca) - { - int save_errno = errno; - free (gf); - __set_errno (save_errno); - } + scratch_buffer_free (&buf); return result; }