From 6c1ab83daaff423f23209f981936473364bda02f Mon Sep 17 00:00:00 2001 From: Konstantin Khorenko Date: Tue, 1 Feb 2011 17:16:29 +0300 Subject: [PATCH] NFSD: memory corruption due to writing beyond the stat array commit 3aa6e0aa8ab3e64bbfba092c64d42fd1d006b124 upstream. If nfsd fails to find an exported via NFS file in the readahead cache, it should increment corresponding nfsdstats counter (ra_depth[10]), but due to a bug it may instead write to ra_depth[11], corrupting the following field. In a kernel with NFSDv4 compiled in the corruption takes the form of an increment of a counter of the number of NFSv4 operation 0's received; since there is no operation 0, this is harmless. In a kernel with NFSDv4 disabled it corrupts whatever happens to be in the memory beyond nfsdstats. Signed-off-by: Konstantin Khorenko Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- fs/nfsd/vfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 3c111120b619f..40962779c6666 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -819,7 +819,7 @@ nfsd_get_raparms(dev_t dev, ino_t ino) if (ra->p_count == 0) frap = rap; } - depth = nfsdstats.ra_size*11/10; + depth = nfsdstats.ra_size; if (!frap) { spin_unlock(&rab->pb_lock); return NULL; -- 2.47.2