Commit c0173863 authored Mar 16, 2012 by Anton Blanchard Committed by Linus Torvalds Mar 16, 2012

afs: Remote abort can cause BUG in rxrpc code



When writing files to afs I sometimes hit a BUG:

kernel BUG at fs/afs/rxrpc.c:179!

With a backtrace of:

	afs_free_call
	afs_make_call
	afs_fs_store_data
	afs_vnode_store_data
	afs_write_back_from_locked_page
	afs_writepages_region
	afs_writepages

The cause is:

	ASSERT(skb_queue_empty(&call->rx_queue));

Looking at a tcpdump of the session the abort happens because we
are exceeding our disk quota:

	rx abort fs reply store-data error diskquota exceeded (32)

So the abort error is valid. We hit the BUG because we haven't
freed all the resources for the call.

By freeing any skbs in call->rx_queue before calling afs_free_call
we avoid hitting leaking memory and avoid hitting the BUG.

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 2c724fb9

fs/afs/rxrpc.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -314,6 +314,7 @@ int afs_make_call(struct in_addr addr, struct afs_call call, gfp_t gfp,
		struct msghdr msg;
		struct kvec iov[1];
		int ret;
		struct sk_buff *skb;

		_enter("%x,{%d},", addr->s_addr, ntohs(call->port));

		@@ -380,6 +381,8 @@ int afs_make_call(struct in_addr addr, struct afs_call call, gfp_t gfp,

		error_do_abort:
		rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT);
		while ((skb = skb_dequeue(&call->rx_queue)))
		afs_free_skb(skb);
		rxrpc_kernel_end_call(rxcall);
		call->rxcall = NULL;
		error_kill_call:

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