>From e5adcd97b5196e29991b524237381a0202a60659 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 9 Feb 2025 10:07:19 -0500 Subject: [PATCH] iconv: fix erroneous input validation in EUC-KR decoder as a result of incorrect bounds checking on the lead byte being decoded, certain invalid inputs which should produce an encoding error, such as "\xc8\x41", instead produced out-of-bounds loads from the ksc table. in a worst case, the loaded value may not be a valid unicode scalar value, in which case, if the output encoding was UTF-8, wctomb would return (size_t)-1, causing an overflow in the output pointer and remaining buffer size which could clobber memory outside of the output buffer. bug report was submitted in private by Nick Wellnhofer on account of potential security implications. --- src/locale/iconv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/locale/iconv.c b/src/locale/iconv.c index 9605c8e9..008c93f0 100644 --- a/src/locale/iconv.c +++ b/src/locale/iconv.c @@ -502,7 +502,7 @@ size_t iconv(iconv_t cd, char **restrict in, size_t *restrict inb, char **restri if (c >= 93 || d >= 94) { c += (0xa1-0x81); d += 0xa1; - if (c >= 93 || c>=0xc6-0x81 && d>0x52) + if (c > 0xc6-0x81 || c==0xc6-0x81 && d>0x52) goto ilseq; if (d-'A'<26) d = d-'A'; else if (d-'a'<26) d = d-'a'+26; -- 2.21.0