Commit 3c0a2e0b authored by Sergey Shtylyov's avatar Sergey Shtylyov Committed by Trond Myklebust
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nfs: fix undefined behavior in nfs_block_bits() 



Shifting *signed int* typed constant 1 left by 31 bits causes undefined
behavior. Specify the correct *unsigned long* type by using 1UL instead.

Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarSergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: default avatarBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent a01b077a

fs/nfs/internal.h

+2 −2
Original line number Diff line number Diff line
@@ -717,9 +717,9 @@ unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp) 
	if ((bsize & (bsize - 1)) || nrbitsp) {

		unsigned char	nrbits;



		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)

		for (nrbits = 31; nrbits && !(bsize & (1UL << nrbits)); nrbits--)

			;

		bsize = 1 << nrbits;

		bsize = 1UL << nrbits;

		if (nrbitsp)

			*nrbitsp = nrbits;

	}