diff options
author | Andy Dougherty <doughera@lafayette.edu> | 2013-01-16 12:30:43 -0500 |
---|---|---|
committer | David Mitchell <davem@iabyn.com> | 2013-03-03 20:06:24 +0000 |
commit | 78c29bba6adca113363434fac1ad2dc15f32aa8b (patch) | |
tree | 514610ade5abaecb2de7b067c2948a905519161e | |
parent | d59e31fc729d8a39a774f03bc6bc457029a7aef2 (diff) | |
download | perl-78c29bba6adca113363434fac1ad2dc15f32aa8b.tar.gz |
Avoid wraparound when casting unsigned size_t to signed ssize_t.
Practically, this only affects a perl compiled with 64-bit IVs on a 32-bit
system. In that instance a value of count >= 2**31 would turn negative
when cast to (ssize_t).
(cherry picked from commit 94e529cc4d56863d7272c254a29eda2b002a4335)
-rw-r--r-- | perlio.c | 8 |
1 files changed, 4 insertions, 4 deletions
@@ -2192,7 +2192,7 @@ PerlIOBase_read(pTHX_ PerlIO *f, void *vbuf, Size_t count) SSize_t avail = PerlIO_get_cnt(f); SSize_t take = 0; if (avail > 0) - take = ((SSize_t)count < avail) ? (SSize_t)count : avail; + take = (((SSize_t) count >= 0) && ((SSize_t)count < avail)) ? (SSize_t)count : avail; if (take > 0) { STDCHAR *ptr = PerlIO_get_ptr(f); Copy(ptr, buf, take, STDCHAR); @@ -4125,7 +4125,7 @@ PerlIOBuf_unread(pTHX_ PerlIO *f, const void *vbuf, Size_t count) */ b->posn -= b->bufsiz; } - if (avail > (SSize_t) count) { + if ((SSize_t) count >= 0 && avail > (SSize_t) count) { /* * If we have space for more than count, just move count */ @@ -4175,7 +4175,7 @@ PerlIOBuf_write(pTHX_ PerlIO *f, const void *vbuf, Size_t count) } while (count > 0) { SSize_t avail = b->bufsiz - (b->ptr - b->buf); - if ((SSize_t) count < avail) + if ((SSize_t) count >= 0 && (SSize_t) count < avail) avail = count; if (flushptr > buf && flushptr <= buf + avail) avail = flushptr - buf; @@ -4450,7 +4450,7 @@ PerlIOPending_read(pTHX_ PerlIO *f, void *vbuf, Size_t count) { SSize_t avail = PerlIO_get_cnt(f); SSize_t got = 0; - if ((SSize_t)count < avail) + if ((SSize_t) count >= 0 && (SSize_t)count < avail) avail = count; if (avail > 0) got = PerlIOBuf_read(aTHX_ f, vbuf, avail); |