From 1c4dd334df3a0627ff57b35612057e2b497e373b Mon Sep 17 00:00:00 2001 From: Paul Cercueil <paul@crapouillou.net> Date: Tue, 1 Sep 2020 16:26:50 +0200 Subject: lib: decompress_unzstd: Limit output size The zstd decompression code, as it is right now, will most likely fail on 32-bit systems, as the default output buffer size causes the buffer's end address to overflow. Address this issue by setting a sane default to the default output size, with a value that won't overflow the buffer's end address. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Reviewed-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> --- lib/decompress_unzstd.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/lib/decompress_unzstd.c b/lib/decompress_unzstd.c index 0ad2c15479ed..790abc472f5b 100644 --- a/lib/decompress_unzstd.c +++ b/lib/decompress_unzstd.c @@ -178,8 +178,13 @@ static int INIT __unzstd(unsigned char *in_buf, long in_len, int err; size_t ret; + /* + * ZSTD decompression code won't be happy if the buffer size is so big + * that its end address overflows. When the size is not provided, make + * it as big as possible without having the end address overflow. + */ if (out_len == 0) - out_len = LONG_MAX; /* no limit */ + out_len = UINTPTR_MAX - (uintptr_t)out_buf; if (fill == NULL && flush == NULL) /* -- cgit