Fix double free in __printf_fp_l (bug 26214).
commitede56038e50235cd1ca7de3602c9491d3b84b49b
authorJoseph Myers <joseph@codesourcery.com>
Thu, 9 Jul 2020 21:51:49 +0000 (9 21:51 +0000)
committerJoseph Myers <joseph@codesourcery.com>
Thu, 9 Jul 2020 21:51:49 +0000 (9 21:51 +0000)
treef9b35a1527c2cb3aa13d8162e29293a331f79b81
parentc363f834cfcbf5efa5449ef13f62233a6d5b9422
Fix double free in __printf_fp_l (bug 26214).

__printf_fp_l has a double free bug in the case where it allocates
memory with malloc internally, then has an I/O error while outputting
trailing padding and tries to free that already-freed memory when the
error occurs.  This patch fixes this by setting the relevant pointer
to NULL after the first free (the only free of this pointer that isn't
immediately followed by returning from the function).

Tested for x86_64 and x86.
stdio-common/Makefile
stdio-common/printf_fp.c
stdio-common/tst-printf-fp-free.c [new file with mode: 0644]