[PATCH 1/2] afs: Read of file returns EBADMSG

From: David Howells
Date: Fri Mar 16 2012 - 06:28:17 EST


From: Anton Blanchard <anton@xxxxxxxxx>

A read of a large file on an afs mount failed:

# cat junk.file > /dev/null
cat: junk.file: Bad message

Looking at the trace, call->offset wrapped since it is only an
unsigned short. In afs_extract_data:


_enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
...

if (call->offset < count) {
if (last) {
_leave(" = -EBADMSG [%d < %zu]", call->offset, count);
return -EBADMSG;
}


Which matches the trace:

[cat ] ==> afs_extract_data({65132},{524},1,,65536)
[cat ] <== afs_extract_data() = -EBADMSG [0 < 65536]

call->offset went from 65132 to 0. Fix this by making call->offset an
unsigned int.

Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
---

fs/afs/internal.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index d2b0888..a306bb6 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -109,7 +109,7 @@ struct afs_call {
unsigned reply_size; /* current size of reply */
unsigned first_offset; /* offset into mapping[first] */
unsigned last_to; /* amount of mapping[last] */
- unsigned short offset; /* offset into received data store */
+ unsigned offset; /* offset into received data store */
unsigned char unmarshall; /* unmarshalling phase */
bool incoming; /* T if incoming call */
bool send_pages; /* T if data from mapping should be sent */

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