From ede56038e50235cd1ca7de3602c9491d3b84b49b Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 9 Jul 2020 21:51:49 +0000 Subject: 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 | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'stdio-common/Makefile') diff --git a/stdio-common/Makefile b/stdio-common/Makefile index 73bf0da296..dc3fd38a19 100644 --- a/stdio-common/Makefile +++ b/stdio-common/Makefile @@ -67,7 +67,8 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \ tst-renameat2 tst-bz11319 tst-bz11319-fortify2 \ scanf14a scanf16a \ tst-printf-bz25691 \ - tst-vfprintf-width-prec-alloc + tst-vfprintf-width-prec-alloc \ + tst-printf-fp-free test-srcs = tst-unbputc tst-printf tst-printfsz-islongdouble @@ -78,11 +79,13 @@ tests-special += $(objpfx)tst-unbputc.out $(objpfx)tst-printf.out \ $(objpfx)tst-setvbuf1-cmp.out \ $(objpfx)tst-vfprintf-width-prec-mem.out \ $(objpfx)tst-printfsz-islongdouble.out \ - $(objpfx)tst-printf-bz25691-mem.out + $(objpfx)tst-printf-bz25691-mem.out \ + $(objpfx)tst-printf-fp-free-mem.out generated += tst-printf-bz18872.c tst-printf-bz18872.mtrace \ tst-printf-bz18872-mem.out \ tst-vfprintf-width-prec.mtrace tst-vfprintf-width-prec-mem.out \ - tst-printf-bz25691.mtrace tst-printf-bz25691-mem.out + tst-printf-bz25691.mtrace tst-printf-bz25691-mem.out \ + tst-printf-fp-free.mtrace tst-printf-fp-free-mem.out endif tests-special += $(objpfx)tst-errno-manual.out @@ -108,6 +111,8 @@ tst-vfprintf-width-prec-ENV = \ MALLOC_TRACE=$(objpfx)tst-vfprintf-width-prec.mtrace tst-printf-bz25691-ENV = \ MALLOC_TRACE=$(objpfx)tst-printf-bz25691.mtrace +tst-printf-fp-free-ENV = \ + MALLOC_TRACE=$(objpfx)tst-printf-fp-free.mtrace $(objpfx)tst-unbputc.out: tst-unbputc.sh $(objpfx)tst-unbputc $(SHELL) $< $(common-objpfx) '$(test-program-prefix)' > $@; \ -- cgit 1.4.1