From 1a9357f443d64aa41e9b0dc414953663a6fcca19 Mon Sep 17 00:00:00 2001 From: Jim Rees Date: Fri, 17 May 2013 17:33:00 -0400 Subject: [PATCH] nfsd: avoid undefined signed overflow In C, signed integer overflow results in undefined behavior, but unsigned overflow wraps around. So do the subtraction first, then cast to signed. Reported-by: Joakim Tjernlund Signed-off-by: Jim Rees Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 91ead0ed9f11..72f0c4e9a942 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3427,7 +3427,7 @@ grace_disallows_io(struct net *net, struct inode *inode) /* Returns true iff a is later than b: */ static bool stateid_generation_after(stateid_t *a, stateid_t *b) { - return (s32)a->si_generation - (s32)b->si_generation > 0; + return (s32)(a->si_generation - b->si_generation) > 0; } static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_session)