New submission from Charles-Francois Natali <neolo...@free.fr>: $ cat /tmp/test_mmap.py import mmap
m = mmap.mmap(-1, 1024, prot=mmap.PROT_READ|mmap.PROT_EXEC) m[0] = 0 $ ./python /tmp/test_mmap.py Segmentation fault When trying to perform a write, is_writable is called to check that we can indeed write to the mmaped area. is_writable just checks the access mode, and if it's not ACCESS_READ, we go ahead and proceed to the write. The problem is that under Unix, it's possible to pass ACCESS_DEFAULT, and in that case no check is done on prot value. In that case, is_writable will return true (since ACCESS_DEFAULT != ACCESS_READ), but if prot doesn't include PROT_WRITE bit, we'll segfault. Attached is a patch including fix and specific test. ---------- files: mmap_check_prot_py3k.diff keywords: patch messages: 130008 nosy: neologix priority: normal severity: normal status: open title: mmap write segfaults if PROT_WRITE bit is not set in prot Added file: http://bugs.python.org/file20991/mmap_check_prot_py3k.diff _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue11391> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
