From 3aa6e0aa8ab3e64bbfba092c64d42fd1d006b124 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 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 Cc: stable@kernel.org Signed-off-by: J. Bruce Fields --- 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 fda3be237773..30c73f8a5791 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -808,7 +808,7 @@ 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;