From 5ae5973bed1947f4d447dc80b76d5cefadd90133 Mon Sep 17 00:00:00 2001 From: Marcus Meissner Date: Sat, 16 May 2020 16:47:42 +0200 Subject: [PATCH] libexif: Fix read buffer overflow (CVE-2020-0093) Make sure the number of bytes being copied from doesn't exceed the source buffer size. From Android repo: https://android.googlesource.com/platform/external/libexif/+/0335ffc17f9b9a4831c242bb08ea92f605fde7a6%5E%21/#F0 Test: testPocBug_148705132 Bug: 148705132 fixes https://github.com/libexif/libexif/issues/42 --- libexif/exif-data.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/libexif/exif-data.c b/libexif/exif-data.c index 6332cd1a..65ae93d5 100644 --- a/libexif/exif-data.c +++ b/libexif/exif-data.c @@ -308,7 +308,9 @@ exif_data_save_data_entry (ExifData *data, ExifEntry *e, /* Write the data. Fill unneeded bytes with 0. Do not crash with * e->data is NULL */ if (e->data) { - memcpy (*d + 6 + doff, e->data, s); + unsigned int len = s; + if (e->size < s) len = e->size; + memcpy (*d + 6 + doff, e->data, len); } else { memset (*d + 6 + doff, 0, s); }