Commit 2c724fb9 authored Mar 16, 2012 by Anton Blanchard Committed by Linus Torvalds Mar 16, 2012

afs: Read of file returns EBADMSG



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@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0c4d0670

fs/afs/internal.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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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