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@xxxxxxxxxxxxxxx>
---
Notes:
v2: Change limit to 1 GiB
v3: Compute size limit instead of using hardcoded value
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)
/*
--
2.28.0
