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author | Joe Simmons-Talbott <josimmon@redhat.com> | 2023-05-26 09:58:27 -0400 |
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committer | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2023-05-26 09:58:27 -0400 |
commit | 02f3d4c53a81f4c9954fbd5502f2e4fe1ab25edd (patch) | |
tree | 6431d8f1cfb4b61d78fd1ad8376a3582d910f33e /sysdeps/unix | |
parent | a363f7075125fa654342c69331e6c075518ec28c (diff) | |
download | glibc-02f3d4c53a81f4c9954fbd5502f2e4fe1ab25edd.zip glibc-02f3d4c53a81f4c9954fbd5502f2e4fe1ab25edd.tar.gz glibc-02f3d4c53a81f4c9954fbd5502f2e4fe1ab25edd.tar.bz2 |
setipv4sourcefilter: Avoid using alloca.
Use a scratch_buffer rather than alloca/malloc to avoid potential stack
overflow.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Diffstat (limited to 'sysdeps/unix')
-rw-r--r-- | sysdeps/unix/sysv/linux/setipv4sourcefilter.c | 24 |
1 files changed, 7 insertions, 17 deletions
diff --git a/sysdeps/unix/sysv/linux/setipv4sourcefilter.c b/sysdeps/unix/sysv/linux/setipv4sourcefilter.c index 7f146d7..8c77ba3 100644 --- a/sysdeps/unix/sysv/linux/setipv4sourcefilter.c +++ b/sysdeps/unix/sysv/linux/setipv4sourcefilter.c @@ -16,12 +16,12 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <alloca.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include <stdint.h> #include <netinet/in.h> +#include <scratch_buffer.h> #include <sys/socket.h> @@ -33,17 +33,12 @@ setipv4sourcefilter (int s, struct in_addr interface, struct in_addr group, /* We have to create an struct ip_msfilter object which we can pass to the kernel. */ size_t needed = IP_MSFILTER_SIZE (numsrc); - int use_alloca = __libc_use_alloca (needed); - struct ip_msfilter *imsf; - if (use_alloca) - imsf = (struct ip_msfilter *) alloca (needed); - else - { - imsf = (struct ip_msfilter *) malloc (needed); - if (imsf == NULL) - return -1; - } + struct scratch_buffer buf; + scratch_buffer_init (&buf); + if (!scratch_buffer_set_array_size (&buf, 1, needed)) + return -1; + struct ip_msfilter *imsf = buf.data; imsf->imsf_multiaddr = group; imsf->imsf_interface = interface; @@ -53,12 +48,7 @@ setipv4sourcefilter (int s, struct in_addr interface, struct in_addr group, int result = __setsockopt (s, SOL_IP, IP_MSFILTER, imsf, needed); - if (! use_alloca) - { - int save_errno = errno; - free (imsf); - __set_errno (save_errno); - } + scratch_buffer_free (&buf); return result; } |