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author | Joe Simmons-Talbott <josimmon@redhat.com> | 2023-05-16 09:45:49 -0400 |
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committer | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2023-05-29 09:16:00 -0400 |
commit | d9055634a34d4bcb242f84f36c9a7bb1c4019076 (patch) | |
tree | 9ffca92c8accf529e527638b17cc00928e15177d /sysdeps/unix | |
parent | 79b2667d1eb06c6503c22f2f323c1c574ac5917b (diff) | |
download | glibc-d9055634a34d4bcb242f84f36c9a7bb1c4019076.zip glibc-d9055634a34d4bcb242f84f36c9a7bb1c4019076.tar.gz glibc-d9055634a34d4bcb242f84f36c9a7bb1c4019076.tar.bz2 |
setsourcefilter: Replace alloca with a scratch_buffer.
Use a scratch_buffer rather than either alloca or malloc to reduce the
possibility of a stack overflow.
Suggested-by: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'sysdeps/unix')
-rw-r--r-- | sysdeps/unix/sysv/linux/setsourcefilter.c | 27 |
1 files changed, 7 insertions, 20 deletions
diff --git a/sysdeps/unix/sysv/linux/setsourcefilter.c b/sysdeps/unix/sysv/linux/setsourcefilter.c index 538f4de..479744f 100644 --- a/sysdeps/unix/sysv/linux/setsourcefilter.c +++ b/sysdeps/unix/sysv/linux/setsourcefilter.c @@ -16,13 +16,10 @@ 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 <sys/socket.h> +#include <scratch_buffer.h> #include "getsourcefilter.h" @@ -34,17 +31,12 @@ setsourcefilter (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. */ size_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); @@ -63,12 +55,7 @@ setsourcefilter (int s, uint32_t interface, const struct sockaddr *group, else result = __setsockopt (s, sol, MCAST_MSFILTER, gf, needed); - if (! use_alloca) - { - int save_errno = errno; - free (gf); - __set_errno (save_errno); - } + scratch_buffer_free (&buf); return result; } |