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author | Joe Simmons-Talbott <josimmon@redhat.com> | 2023-05-30 14:13:40 -0400 |
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committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-06-01 14:46:09 -0300 |
commit | d1eaab5a7932cda190cbbfa657c684059b141c19 (patch) | |
tree | 9ca36cb571cc82feec4154c8706319c3cfaae49a /sysdeps/unix | |
parent | 29e25f6f136182fb3756d51e03dea7c4d1919dd9 (diff) | |
download | glibc-d1eaab5a7932cda190cbbfa657c684059b141c19.zip glibc-d1eaab5a7932cda190cbbfa657c684059b141c19.tar.gz glibc-d1eaab5a7932cda190cbbfa657c684059b141c19.tar.bz2 |
getsourcefilter: Get rid of alloca.
Use a scratch_buffer rather than alloca to avoid potential stack
overflows.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'sysdeps/unix')
-rw-r--r-- | sysdeps/unix/sysv/linux/getsourcefilter.c | 24 |
1 files changed, 7 insertions, 17 deletions
diff --git a/sysdeps/unix/sysv/linux/getsourcefilter.c b/sysdeps/unix/sysv/linux/getsourcefilter.c index b9ba58c..461ad88 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 <https://www.gnu.org/licenses/>. */ -#include <alloca.h> #include <assert.h> #include <errno.h> #include <stdlib.h> +#include <scratch_buffer.h> #include <string.h> #include <stdint.h> #include <netatalk/at.h> @@ -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; } |