nfsd4: fix bad bounds checking

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A number of spots in the xdr decoding follow a pattern like

	n = be32_to_cpup(p++);
	READ_BUF(n + 4);

where n is a u32.  The only bounds checking is done in READ_BUF itself,
but since it's checking (n + 4), it won't catch cases where n is very
large, (u32)(-4) or higher.  I'm not sure exactly what the consequences
are, but we've seen crashes soon after.

Instead, just break these up into two READ_BUF()s.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

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This commit is contained in:

J. Bruce Fields 2016-02-29 20:21:21 -05:00

parent b7052cd7bc

commit 4aed9c46af

1 changed files with 8 additions and 5 deletions

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fs/nfsd/nfs4xdr.c

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