| Message ID | 20230613191631.1080455-1-josimmon@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v4] grantpt: Get rid of alloca | expand |
Applied, thanks! Joe Simmons-Talbott, le mar. 13 juin 2023 15:16:31 -0400, a ecrit: > Replace alloca with a scratch_buffer to avoid potential stack overflows. > --- > Changes since v3: > * Explicitly set the retval for scratch_buffer_set_array_size failure. > > sysdeps/unix/grantpt.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/sysdeps/unix/grantpt.c b/sysdeps/unix/grantpt.c > index 38fce52576..226e7adb75 100644 > --- a/sysdeps/unix/grantpt.c > +++ b/sysdeps/unix/grantpt.c > @@ -20,6 +20,7 @@ > #include <fcntl.h> > #include <grp.h> > #include <limits.h> > +#include <scratch_buffer.h> > #include <stdlib.h> > #include <string.h> > #include <sys/resource.h> > @@ -147,10 +148,19 @@ grantpt (int fd) > /* `sysconf' does not support _SC_GETGR_R_SIZE_MAX. > Try a moderate value. */ > grbuflen = 1024; > - grtmpbuf = (char *) __alloca (grbuflen); > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > + if (!scratch_buffer_set_array_size (&sbuf, 1, grbuflen)) > + { > + retval = -1; > + goto cleanup; > + } > + grtmpbuf = sbuf.data; > __getgrnam_r (TTY_GROUP, &grbuf, grtmpbuf, grbuflen, &p); > if (p != NULL) > tty_gid = p->gr_gid; > + > + scratch_buffer_free(&sbuf); > } > gid_t gid = tty_gid == -1 ? __getgid () : tty_gid; > > -- > 2.39.2 >
diff --git a/sysdeps/unix/grantpt.c b/sysdeps/unix/grantpt.c index 38fce52576..226e7adb75 100644 --- a/sysdeps/unix/grantpt.c +++ b/sysdeps/unix/grantpt.c @@ -20,6 +20,7 @@ #include <fcntl.h> #include <grp.h> #include <limits.h> +#include <scratch_buffer.h> #include <stdlib.h> #include <string.h> #include <sys/resource.h> @@ -147,10 +148,19 @@ grantpt (int fd) /* `sysconf' does not support _SC_GETGR_R_SIZE_MAX. Try a moderate value. */ grbuflen = 1024; - grtmpbuf = (char *) __alloca (grbuflen); + struct scratch_buffer sbuf; + scratch_buffer_init (&sbuf); + if (!scratch_buffer_set_array_size (&sbuf, 1, grbuflen)) + { + retval = -1; + goto cleanup; + } + grtmpbuf = sbuf.data; __getgrnam_r (TTY_GROUP, &grbuf, grtmpbuf, grbuflen, &p); if (p != NULL) tty_gid = p->gr_gid; + + scratch_buffer_free(&sbuf); } gid_t gid = tty_gid == -1 ? __getgid () : tty_gid;