This shouldn't happen under any normal circumstances. However, it looks like
it's possible to achieve this with corrupted images. Without this patch
raw_pread is hanging in an endless loop in such cases.
The patch is not affecting growable files, for which such reads happen in
normal use cases. raw_pread_aligned already handles these cases and won't
return zero in the first place.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/raw-posix.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 4d79881..6ef1cff 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -403,8 +403,12 @@ static int raw_pread(BlockDriverState *bs, int64_t offset,
size = ALIGNED_BUFFER_SIZE;
ret = raw_pread_aligned(bs, offset, s->aligned_buf, size);
- if (ret < 0)
+ if (ret < 0) {
return ret;
+ } else if (ret == 0) {
+ fprintf(stderr, "raw_pread: read beyond end of file\n");
+ abort();
+ }
size = ret;
if (size > count)
--
1.6.5.2
