From 49d9742daf6fc7cf638b621ab6066fb1f72cfccc Mon Sep 17 00:00:00 2001 From: Simon Josefsson Date: Tue, 15 Mar 2005 22:31:05 +0000 Subject: [PATCH] Sync with libc. --- lib/ChangeLog | 10 ++++++++++ lib/iconvme.c | 18 +++++++++++++++--- 2 files changed, 25 insertions(+), 3 deletions(-) diff --git a/lib/ChangeLog b/lib/ChangeLog index 5d07911fa2..b0d2e540d4 100644 --- a/lib/ChangeLog +++ b/lib/ChangeLog @@ -1,3 +1,13 @@ +2005-03-08 Paul Eggert + + * iconvme.c (SIZE_MAX): New macro, if not already defined. + (iconv_string): Don't guess a size-zero buffer, as that might cause + buffer overrun. Instead, avoid multiplying by MB_LEN_MAX if the + result would be 'too large', where 'too large' is (heuristically) + the square root of SIZE_MAX, divided by MB_LEN_MAX to allay + overflow concerns. This will prevent some unwanted malloc failures + when the inputs are very large. + 2005-03-15 Bruno Haible * regex.c (byte_re_match_2_internal): Rename local variable 'not' to diff --git a/lib/iconvme.c b/lib/iconvme.c index 68d7f1aca4..4074c7811e 100644 --- a/lib/iconvme.c +++ b/lib/iconvme.c @@ -41,10 +41,14 @@ #if HAVE_ICONV /* Get iconv etc. */ # include -/* Get MB_LEN_MAX. */ +/* Get MB_LEN_MAX, CHAR_BIT. */ # include #endif +#ifndef SIZE_MAX +# define SIZE_MAX ((size_t) -1) +#endif + /* Convert a zero-terminated string STR from the FROM_CODSET code set to the TO_CODESET code set. The returned string is allocated using malloc, and must be dellocated by the caller using free. On @@ -63,10 +67,18 @@ iconv_string (const char *str, const char *from_codeset, char *p = (char *) str; size_t inbytes_remaining = strlen (p); /* Guess the maximum length the output string can have. */ - size_t outbuf_size = (inbytes_remaining + 1) * MB_LEN_MAX; - size_t outbytes_remaining = outbuf_size - 1; /* -1 for NUL */ + size_t outbuf_size = inbytes_remaining + 1; + size_t outbytes_remaining; size_t err; int have_error = 0; + + /* Use a worst-case output size guess, so long as that wouldn't be + too large for comfort. It's OK if the guess is wrong so long as + it's nonzero. */ + size_t approx_sqrt_SIZE_MAX = SIZE_MAX >> (sizeof (size_t) * CHAR_BIT / 2); + if (outbuf_size <= approx_sqrt_SIZE_MAX / MB_LEN_MAX) + outbuf_size *= MB_LEN_MAX; + outbytes_remaining = outbuf_size - 1; #endif if (strcmp (to_codeset, from_codeset) == 0) -- 2.30.2