The patch below does not apply to the .37-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From d1205f87bbb8040c1408bbd9e0a720310b2b0b9b Mon Sep 17 00:00:00 2001 From: Chuck Lever <[email protected]> Date: Fri, 28 Jan 2011 12:41:05 -0500 Subject: [PATCH] NFS: NFSv4 readdir loses entries On recent 2.6.38-rc kernels, connectathon basic test 6 fails on NFSv4 mounts of OpenSolaris with something like: > ./test6: readdir > ./test6: (/mnt/klimt/matisse.test) didn't read expected 'file.12' dir > entry, pass 0 > ./test6: (/mnt/klimt/matisse.test) didn't read expected 'file.82' dir > entry, pass 0 > ./test6: (/mnt/klimt/matisse.test) didn't read expected 'file.164' dir > entry, pass 0 > ./test6: (/mnt/klimt/matisse.test) Test failed with 3 errors > basic tests failed > Tests failed, leaving /mnt/klimt mounted > [cel@matisse cthon04]$ I narrowed the problem down to nfs4_decode_dirent() reporting that the decode buffer had overflowed while decoding the entries for those missing files. verify_attr_len() assumes both it's pointer arguments reside on the same page. When these arguments point to locations on two different pages, verify_attr_len() can report false errors. This can happen now that a large NFSv4 readdir result can span pages. We have reasonably good checking in nfs4_decode_dirent() anyway, so it should be safe to simply remove the extra checking. At a guess, this was introduced by commit 6650239a, "NFS: Don't use vm_map_ram() in readdir". Cc: [email protected] [2.6.37] Signed-off-by: Chuck Lever <[email protected]> Signed-off-by: Trond Myklebust <[email protected]> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 009aef9..4e2c168 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -6132,9 +6132,6 @@ int nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, if (entry->fattr->valid & NFS_ATTR_FATTR_TYPE) entry->d_type = nfs_umode_to_dtype(entry->fattr->mode); - if (verify_attr_len(xdr, p, len) < 0) - goto out_overflow; - return 0; out_overflow: _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
