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| author | Joseph Myers <joseph@codesourcery.com> | 2020-07-09 21:51:49 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2020-07-09 21:51:49 +0000 |
| commit | ede56038e50235cd1ca7de3602c9491d3b84b49b (patch) | |
| tree | f9b35a1527c2cb3aa13d8162e29293a331f79b81 /stdio-common/printf_fp.c | |
| parent | c363f834cfcbf5efa5449ef13f62233a6d5b9422 (diff) | |
| download | glibc-ede56038e50235cd1ca7de3602c9491d3b84b49b.zip glibc-ede56038e50235cd1ca7de3602c9491d3b84b49b.tar.gz glibc-ede56038e50235cd1ca7de3602c9491d3b84b49b.tar.bz2 | |
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.
Diffstat (limited to 'stdio-common/printf_fp.c')
| -rw-r--r-- | stdio-common/printf_fp.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/stdio-common/printf_fp.c b/stdio-common/printf_fp.c index 9e0ce96..49c6935 100644 --- a/stdio-common/printf_fp.c +++ b/stdio-common/printf_fp.c @@ -1250,6 +1250,9 @@ __printf_fp_l (FILE *fp, locale_t loc, { free (buffer); free (wbuffer); + /* Avoid a double free if the subsequent PADN encounters an + I/O error. */ + wbuffer = NULL; } } |