Messages in this thread Patch in this message | | | Date | Sun, 24 Apr 2022 16:48:20 -0400 (EDT) | From | Mikulas Patocka <> | Subject | [PATCH] hex2bin: fix access beyond string end |
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If we pass too short string to "hex2bin" (and the string size without the terminating NUL character is even), "hex2bin" reads one byte after the terminating NUL character. This patch fixes it.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org
--- lib/hexdump.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
Index: linux-2.6/lib/hexdump.c =================================================================== --- linux-2.6.orig/lib/hexdump.c 2022-04-24 18:51:16.000000000 +0200 +++ linux-2.6/lib/hexdump.c 2022-04-24 18:51:16.000000000 +0200 @@ -45,10 +45,13 @@ EXPORT_SYMBOL(hex_to_bin); int hex2bin(u8 *dst, const char *src, size_t count) { while (count--) { - int hi = hex_to_bin(*src++); - int lo = hex_to_bin(*src++); + int hi, lo; - if ((hi < 0) || (lo < 0)) + hi = hex_to_bin(*src++); + if (hi < 0) + return -EINVAL; + lo = hex_to_bin(*src++); + if (lo < 0) return -EINVAL; *dst++ = (hi << 4) | lo;
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